307 Olds V-8, overhaul or remanufactured?

[JCK55buick]

After almost buying an '85 Riv with the V-6 turbo, decided to invest the funds in restoring my '83 Riv convertible.  Rare car, and I enjoy it very much, but the paint is very tired and engine is smoking, about 106,000 miles on it.

I am a nut for keeping everything original.  Waiting for some quotes, but I am guessing to completely overhaul the engine is going to be far more expensive than a remanufactured engine of the same size.  This is never going to be a million dollar car, but am I hurting its future value when my nieces and nephews sell it after I am gone?  Is there even a way to tell that the 307 V8 is not the one that came in it from the factory (are there numbers matching (body/engine) in 1983?)

Thanks, fellow ROA members, I appreciate your input.

[John2012]

Numbers matching is important for a limited number of cars.  A 1983 Riviera is not one of them.  If it is more financially feasible to get a good used 307 as opposed to a rebuild of the original I would go that route.  

[dship]

1 hour ago, John2012 said:

Numbers matching is important for a limited number of cars.  A 1983 Riviera is not one of them.  If it is more financially feasible to get a good used 307 as opposed to a rebuild of the original I would go that route.  

I agree. I don't believe it is important for the 6th generation Rivieras to be numbers matching....don't even know if there are any numbers to be matched.

[Ben Bruce aka First Born]

DON'T WORRY ABOUT AFTER YOU ARE GONE!   This is one time that living in the "now" is better.  My 2 cents.

 

  Ben

[JCK55buick]

I agree Ben, I try to drive one of my cars every nice day we get! (Not now while we have snow on the ground.)  But I still want to have a plan, I have no children to leave them to, so likely they will be sold and I will leave the money to several charities.  I volunteer every weekend at our local Classic Car Collection.  The gentleman who donated 136 restored cars to get us started was in his 80s and wondering what to do with his collection.  He kept around 30 cars for his kids, but donated the rest.  Now we are fighting to keep it open and keep our city and county from selling off the cars at auction!  Just like the Hudson guy in Indiana, what a rotten shame to sell off his collection after his death and after he donated them to the city.  sorry to rant and rave, our CCC is very near and dear to my heart!  Merry Christmas, Buick lovers!

[J3Studio]

6 hours ago, John2012 said:

Numbers matching is important for a limited number of cars.  A 1983 Riviera is not one of them.  If it is more financially feasible to get a good used 307 as opposed to a rebuild of the original I would go that route.  

 

I concur, especially since the numbers-matching crowd (and I know many of them) will already shy away because of the 106,000 miles. Get a good used 307 and drive that Riviera!

[J3Studio]

5 hours ago, dship said:

I agree. I don't believe it is important for the 6th generation Rivieras to be numbers matching....don't even know if there are any numbers to be matched.

 

I find it hard to believe that GM varied significantly across its product lines in this portion of the production process within the same era, so there are probably numbers to match. Their existence does not mean that they can be easily found or deciphered—or that many care to. Perhaps when @JCK55buick pulls the original engine, he can examine it for number stampings—if he is so inclined.

Edited December 22, 2020 by J3Studio (see edit history)

[60FlatTop]

I wouldn't be concerned about the numbers, but I would be inclined to have the original rebuilt just to keep the parts the same. You could run into some GM related issue where the eighth digit of the VIN code was different an something won't fit or work with your engine. Don't trust an engine mass production shop to understand those subtleties. Your engine rebuilt will be correct for your car. It may not be an issue but why risk it.

 

When we rebuilt the engine in my '86 Park Ave a no oil pressure on start up led us to find there are two timing chain cover gaskets, maybe more, for the 3.8 6. Out first one had the oil passage hole in the wrong place. Some of that information is not readily available on these later (only 35 year old) cars.

 

We got it though!

[RivNut]

I wouldn't be concerned about numbers matching either.  Going for a rebuild leaves you with what you had.  IF it were me, and that's a big if, I would consider a rebuilt Oldsmobile 350 from a era that had some horsepower. I've owned 5 of these; 84, and 85 coupes,  84 convertible, and two 83 XX Anniversary cars.  Loved every one of them but hated the doggie performance.  As a friend of mine who calls his Eldorado with the same engine his "Flat lander town car."  Meaning it doesn't have the oomph to cruise easily at modern highway speeds - remember the speedometer has 55 in big numbers; wasn't designed to cruise at 70 - 75 all day long. And it's not a car that takes to the hills easily either.  Under powered and long in the tooth. 2.79 axle ratio, overdrive transmission, and a lockup torque converter don't make for a smooth drive through rolling hills. Early smog motor and carburetor don't help much either.  If possible find a 79 Riviera to drive that is powered by a 350 engine and you'll know what a difference there is. Might be worthy of consideration.  If you really want to be bold, look for the 403 (6.6  liter) Oldsmobile engine that was used in the Pontiac Firebird Trans Am - think Smokey and the bandit.  (6.6 Trans Ams with an automatic transmission used the 403 Oldsmobile; the same Trans Am with  4 speed used the 400 Pontiac engine.)

[J3Studio]

1 hour ago, RivNut said:

I wouldn't be concerned about numbers matching either.  Going for a rebuild leaves you with what you had.  IF it were me, and that's a big if, I would consider a rebuilt Oldsmobile 350 from a era that had some horsepower. I've owned 5 of these; 84, and 85 coupes,  84 convertible, and two 83 XX Anniversary cars.  Loved every one of them but hated the doggie performance.  As a friend of mine who calls his Eldorado with the same engine his "Flat lander town car."  Meaning it doesn't have the oomph to cruise easily at modern highway speeds - remember the speedometer has 55 in big numbers; wasn't designed to cruise at 70 - 75 all day long. And it's not a car that takes to the hills easily either.  Under powered and long in the tooth. 2.79 axle ratio, overdrive transmission, and a lockup torque converter don't make for a smooth drive through rolling hills. Early smog motor and carburetor don't help much either.  If possible find a 79 Riviera to drive that is powered by a 350 engine and you'll know what a difference there is. Might be worthy of consideration.  If you really want to be bold, look for the 403 (6.6 liter) Oldsmobile engine that was used in the Pontiac Firebird Trans Am - think Smokey and the Bandit.  (6.6 Trans Ams with an automatic transmission used the 403 Oldsmobile; the same Trans Am with  4 speed used the 400 Pontiac engine.)

 

Thanks for the reality check from someone who was there—I often forget that my particular eighties car is way to the right of the contemporary performance bell curve. The funny thing is that by 1982 the Riviera was in much better powertrain shape than the Eldorado, who had to go with the 135 bhp HT-4100.

It's interesting to think about swapping in the 1979/1980 350 ci engine.

Edited December 22, 2020 by J3Studio (see edit history)

[RivNut]

I just Googled  "6th generation Riviera engine swap" and found thread about one guys experience in putting a 403 from a 79 Pontiac TA into his 82 Riviera.  It was a drop in but he had to use the original oil pan and exhaust manifolds.  You can probably find it like I did or just search the Riviera Owners forum on this site.  If you were to go this far, you should consider dual exhaust as well as an improvement in a camshaft. There used to be an Oldsmobile site that dealt a lot with different Oldsmobile engines.  I referred to it a lot when I wanted to put a 310 hp 350 Oldsmobile Rocket engine (sold but I know where it's sitting) I had from a 69 Cutlass and 200-4R (which I still have) combo into an 83 Regal I had.  It was a go until my stepson wrecked the Regal.  😫

[psychostang]

If I may give my opinion.  I would remove/disassemble/inspect the 307.  Then clean the chambers and pistons of carbon.  Do a dingle ball hone to all cylinders.  Then re-ring and replace bearings, then reassemble.  Then just enjoy the vehicle.  Let the next person spend the money on performance mods.

[RivNut]

I wasn't intending for the engine to be built to any kind of muscle car performance standards, just trying to suggest what could be done to make it drivable in today's traffic.  I drove my 85 coupe home from the 2010 meet and came through the mountains of West Virginia.  One of the most miserable trips I've  made in a Riviera. It could not handle being driven in the mountains. I was being passed by 18 wheelers going uphill. Once i go to the flats, 70 mph seemed to push it as well.  Just my experience.  Because  of the comfort, I would drive another one in a heart beat - IF it had an engine that would allow it to be driven on today's  roads.  Those 307 Old's engines are dinosaurs of the 55 mph era and early attempts at emissions controls. They are 35 years old which is a bunch for a 145 horsepower engine. 

[60FlatTop]

2 hours ago, RivNut said:

One of the most miserable trips I've  made in a Riviera.

Arnie responded to a Facebook ad for a 403 for sale at the gravel pit 'cause he couldn't get no satisfaction from his 307.

 

Moot point.

 

[J3Studio]

3 minutes ago, 60FlatTop said:

Arnie responded to a Facebook ad for a 403 for sale at the gravel pit 'cause he couldn't get no satisfaction from his 307.

 

At least he has the upmarket radio …

[Bloo]

If you are going to do this changeover at all, get the Olds 350. It is a stellar engine. While the 307 and 403 were similar high quality, the 307 was widely panned for it's lack of power, and the 403 was a bit disappointing as well. The 403, in hindsight, isn't very well thought out compared to it's predecessors. Neither is a good starting point when there are Olds 350s laying around.

 

In an 85 you would probably have to lose the electronic engine controls. I'm a bit on the fence about that one because I think it is a good system, but parts availability and cost could be a problem today.

[JCK55buick]

Thanks for all of the responses; I really appreciate the input.  I did attempt to drive my Riv to the BCA meet in Danvers, Mass, back in 2011.  We got as far as Princeton, Illinois, and the transmission gave out, would not shift out of 2nd.  Left it with a GM dealer there, was eventually overhauled by an independent tranny shop.  Works fine now, except for the constant small leak.  It is not a powerful engine, but I live on the plains of Nebraska and it really does not bother me.  I have driven it several times to Lincoln (130 miles) on I-80, and got along fine.  It is primarily used as a summer cruise around town car, out for ice cream on a Tuesday night!

I am going to think long and hard about the 350, that may be a good compromise.  It will be interesting to see what the cost difference is between rebuilding my engine and a remanufactured either 307 or 350.

 

I am adding a pic of my Riv on Tour Nebraska, another great way to enjoy it!  The tour goes on two lane roads, so max 65, and we go 300 miles on a Saturday, and another 300 miles on Sunday. Party on Saturday night, but not too late, as the tour leaves promptly at 7 a.m. the next morning!  Get to see lots of nice country that I have missed, even living in Nebraska my whole life.

 

Today we are in the middle of blizzard conditions, so no collector cars are out on the road!  A blessed Christmas, everyone!

 

[J3Studio]

Kearney to Danvers would have been a hike in any eighties car. We drove through Kearney on our Lincoln Highway trip in our 1985 Corvette in April 2014—stopping (of course) to take pictures with the Covered Wagon.

 

 

At that point, we were about halfway through the Lincoln Highway portion of that 6,300 mile trip.

Edited December 24, 2020 by J3Studio (see edit history)

[J3Studio]

One last thought—I wonder if anyone has tried the modifications made to the 307 for the eighties Oldsmobile 4-4-2 on the Riviera. They would allegedly buy an extra 35 bhp.

[JCK55buick]

The Covered Wagon!  Drove by it so many times as a kid, my Dad's farm was just 3/4 mile west of there, and Mom said we had to live in town!   Unfortunately, it does not look that good today, the canvas over the wagon has been ripped apart by the winds, and the owner has not replaced it yet.  We were known for many years as the Midway City, 1733 miles to Boston, 1733 to San Francisco.  Our town hosted the big celebration of the 100th anniversary of the Lincoln Highway, that may have been in 2014, time seems to slip by me!

 

I like your idea about the 4-4-2 modification, I am going to investigate that with my mechanic.

[RivNut]

21 hours ago, J3Studio said:

One last thought—I wonder if anyone has tried the modifications made to the 307 for the eighties Oldsmobile 4-4-2 on the Riviera. They would allegedly buy an extra 35 bhp.

That's still only 180 hp.  The 1.3 liter 3 cylinder engine in my EncoreGX has about that many and it probably weighs 1,000 lbs less.  I think 250 hp would be a good target.

[J3Studio]

5 minutes ago, RivNut said:

That's still only 180 hp.  The 1.3 liter 3 cylinder engine in my EncoreGX has about that many and it probably weighs 1,000 lbs less.  I think 250 hp would be a good target.

 

Tons more torque, though. I made the 4-4-2 suggestion because many of the parts seem to be readily available.

[RivNut]

21 hours ago, J3Studio said:

One last thought—I wonder if anyone has tried the modifications made to the 307 for the eighties Oldsmobile 4-4-2 on the Riviera. They would allegedly buy an extra 35 

The 1969 Oldsmobile Cutlass S came with a 250 hp 350 cubic inch V8.  Probably a R&R.  No emissions controls though. You would need to use the 307's oil pan and exhaust manifolds. (Ditch the catalytic converter and put on dual exhausts.)

[60FlatTop]

Try driving one of those '80's cars without using overdrive for a couple of weeks. If you like it pick up a ring and pinion a notch up or just quit using the OD altogether.

 

When I commuted to work the expressway ended about 7 miles from my house. I would drop the newer cars out of OD for those last few miles and come home smiling. I think one of my biggest enjoyments of my '64 Riviera is that it always runs 1:1, a wonderful and noticeable feeling.

[Lesabre T-type Chris]

Hello Jeff,

 

I read your original post along with the follow-ups and thought I would chime in.  This will be long but I believe it will be helpful for you...

 

Back in the 90's through the early 2000's I owned an '85 LeSabre Limited Collector's Edition 4-door (GM B-body, RWD, Olds 307 V-8).  It was my daily driver and I really loved her.  My dad had a 1977 LeSabre 4-door (GM B-body, RWD, Pontiac 301 V-8 ) that I grew up with so you could say that I have an affinity for Buick B-bodies from my childhood.  The '85 LeSabre was loaded with almost every option for that model year--in many ways like an Electra or Park Avenue during that time period.  Without question she was very reliable, smooth, quiet, and comfortable.  If I wasn't hard on her, on long trips I could get MPG's in the low 20's @ 70/75 mph and ride in extreme comfort with little wind/road noise.  If I could have changed anything about her, I really wished she would have been a coupe with the Buick Rally/Road wheels and that she would have had more 'get-up-and-go.'  I finally parted with her around 2002 because the Wisconsin winters and road salt had taken their toll on her underbody and it was just too much to keep her up.  I really loved that car and miss her terribly to this day.  I always wanted another car like her although my preference would be to get a 2-door if I could find one.  Low and behold, around fall 2016 I stumbled upon a 1977 Buick Riviera (GM B-Body, RWD, Olds 403 V-8) and was hooked as they are on the same platform and share a lot of traits.  With the kids almost grown up the time was right to get back into the car game/hobby and I bought her!  Do you want to talk about nostalgia?  Holy cow!  And, I have to say, while the Olds 403 in my '77 Riviera is not a dragster in stock form, the driving difference between the 307 that was in my '85 LeSabre and the 403 in my '77 Riviera is quite noticeable.  I know that the comparison to your FWD E-body Riviera is a little bit apples-to-oranges but I am in 100% agreement with Ed (RivNut) that if you are going to be making a decision about the future of your 307 you should really consider your options.  I have been conducting a LOT of research on the Olds 'Rocket' V-8's and Buick V-6/V-8 over the last year or so because I am planning the future for my '77 Riviera.  She's almost all original and has just under 70,000 miles so she is in good enough shape to do some things with but not a 'sought after collector' that must stay original (unless I would desire to 'stay original').  I can go in whatever direction I want to with her.  Here are some thoughts I can share with you....

• Take Ed's suggestion before you do anything to your current car.  With some detective work, find a 1979 or 1980 Riviera in good running condition that came equipped from the factory with the Olds 350 V-8 and take it for a test drive.  Thoroughly drive your '83 with the 307 beforehand.  You should be able to feel the performance difference when driving them back-to-back.  The 350 equipped Riviera still won't be a hot rod but you should notice it is going to get-up-and go/cruise better than your 307 powered Riviera.  With my '77 Riviera and her 403 I remember thinking to myself on the test drive, 'Wow, THIS is how GM intended these downsized B-bodies to be powered when they designed them back in '77!  The 403 gets off the line better, pulls better when going down the highway, and cruises super quiet.  That is low-end torque at work which the 307 just has less of!  The 403 is rated at 320 ft-lb. (net) from the factory and the 307 (depending on year) is between 240-255 ft-lb. from the factory.  The difference in the acceleration and performance you 'feel' is (partially) in the cubic inches of the motor and (partially) in the gearing of the transmission/differential.  My instincts say you will drive the 350 powered Riviera and say something similar.  This will make your decision on what to do a lot easier!
• If you stay with an Olds 307 in your '83 and are happy that is great and I mean that when I say it as it is your car!  I'd have the original motor removed, rebuilt, and reinstalled and keep it all original if you go that route.  Know, though, that the 307 is pretty much what it is.  If you ever would want to put some performance into it, or just get a little more exciting driving experience, you will face a large uphill battle to overcome it's inherent limitations, lack of aftermarket support, and the cost involved in getting more power out of it (ANY motor can be made to make more power but $$$$ will likely cause you to either not do it or get really frustrated--that would be reflected in a rebuild situation too).  Not good, not bad, just what it is!  Chevy guys run into this with the old small-block Chevy 305/350 all the time.  The Chevy 305 can be made to make some power but it costs a lot of $$$$ and you can flat out do more for less $ with a Chevy 350!  If you go with an Olds 350/403 upgrade in your '83, know that even in a stock-type upgrade, you will see performance/driving gains although you will likely lose a little fuel economy.  If you want to do something a little more fun and/or performance oriented (either up-front or later down the road) you will have LOTS of options with the Olds 350 and some with the Olds 403.  The Olds 350 has quite a bit of aftermarket support and options for increasing performance while still being reliable.  The Olds 403 is similar but it does have some limitations (kind of like the 307, the 403 has some inherent design aspects that make it tricky and more costly to increase performance) so $$$$ to wake up the 403 can actually be higher than getting more performance from the Olds 350.
• The small-block Olds 'Rocket' V-8's include the 260, 307, 330, 350, and 403 so the external dimensions of the block and the exterior appearance are the same (or very similar) for all of those engines.  The same is true for the transmission bolt pattern and engine accessories (i.e. water pump, power steering, alternator brackets, cruise control, etc...) as they will almost all bolt up directly to any of those engines without any (or with only little) modification.  This really simplifies things because you (or your builder) will be able to pull out your existing 307 and re-use a lot of the brackets, components, and other accessories on either an Olds 350 or 403 and they will line right up.  A very 'stock-looking appearance' with upgraded internals and performance is very possible if you so desire.  Again, as Ed said, the biggest challenge will be that some of the FWD E-Body stuff on your '83 Riv. is unique in comparison to the RWD set-ups that your donor engine will likely come from (oil pan, exhaust manifolds, etc...) so a number of pieces will need to be transplanted.
• As long as you don't do anything too radical, your transmission and any related drivetrain components will likely be able to handle a minor engine upgrade like this unless you deliberately and repeatedly release your inner teenage-male self that is buried deep inside you (anything can be destroyed if abused, right?) so be smart about that.  To my knowledge, the transmission/axle set-up in your Riviera is basically a longitudinal front wheel drive set-up that Olds developed all the way back in the 60's and it was used with the Olds 455 into the 70's as well as the Turbo 3.8 V6 in the 80's so it can be made to handle power (someone correct me if I am wrong on that). If you get real performance oriented, know that you'll have to take a look at that part of the drivetrain too at some point to be safe in the long-run.

I hope that helps you.  From my end, I am 95% set on first upgrading the transmission and rear-end gears on my '77 Riviera--adding an overdrive transmission and ditching the highway gears (going from a 2.41 rear end to a 3.73 rear end with posi-traction will help acceleration off the line although the overdrive gear will still make her a great highway cruiser).  We'll see what that does first before I make a final engine decision.  I can tell you that I took the plunge last year when the exhaust system was nearing it's end--I upgraded to a later B-body true dual exhaust after the exhaust manifolds all the way back to the tail pipes and that woke up the 403 a bit (she sounds better too)!  Whether you stay with the 307 or upgrade to a 350/403, do research on upgrading the exhaust.  You can keep it quiet if you want although some gains in power can be made if it is a more free-flowing system.

 

-Chris

[RivNut]

The transmission in the original FWD Toronado was a TH425 transaxle (new nomenclature for the chain driven TH400 for front wheel drive) that mounted to the 425 cubic inch engine.  I don't know if one of those could be made to fit in the 79 - 85 chassis.  But I don't think you want to go this far. 😁