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Toasted 455 - What to do next?


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I am a proud owner of a 67 Lark 2dr. Ht. The previous owner swapped in a 455 and a TH400 and did a top end rebuild. The block is either a 75 or 76 with stock heads, a mild/stock cam, and an aluminum intake and Holley carb. I seized up the engine on a hot day courtesy of a short circuited temperature gage, so it's sitting in storage for the winter awaiting it's fate. My question is this: knowing that this in not the stock engine anyways do I put approximately $3K into the rebuild or try to purchase a used engine for considerably less money. I am a college student so money is a factor, as well is the space and time needed to do a swap myself. Basically, is this engine worth sticking that money into or do I start over, perhaps with a pre-built TA long block, for a similar price? I would appreciate any help that you guys can give. Thank you in advance.

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I'd go with a TA block, short or long is up to you. If you are unsure about the condition of the heads then I think a long block is the way to go. Otherwise, just use your previously rebuilt heads and go for a short block.<P>Matthew

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Short block generally means block, crank pisotns & rods, cam. Long block is usually short block plus heads and valve train, sometimes intake.<P>If money is the driving factor, why not pull out your current motor and see what is locked up. You may find that you can get it going again for far less than $3k.

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Talk to car club members and people at shows and find the better rebuilders in your area.<BR>Go check out the shops. Find one you like and discuss your options.. IE.. You pull engine and bring it in for rebuild (cheapest) They pull and rebuild it (Add at least 1000.00) Buy an already done long Block and install it your self. There are lots of options. You should spend 2000.00 to 2500.00 max. Best of all most GOOD shops will give you at least 12 months of warranty.<P>------------------<BR>Gatomon

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Thanks for all your advice, I found a shop in town who would pull and install and do the rebuild with a performance cam and forged pistons for 2,400 complete. Including machining heads and crank and everything else. I thought it was a really good deal. I'm trying to build her up to about 500 hp or so, which I'm told is fairly easy with a cam, piston, valve job. With that hp gain will I need to do anything to my TH400, ie. stall converter, or to the rear differential, currently a BOP 10 bolt with open diff. and 2.73 gears or so. I had planned on going mid 3's with a posi but probably not til next fall. Am I going to hurt anything besides having one very bald tire? Also any suggestions for a specific ratio...possibly going to a 12 bolt? It will be a street car, but I want to be able to beat the pants off those punk kids with 5.0 Stangs and possibly do a few runs at the track for fun. Thanks for your help.<p>[This message has been edited by 67 Skylark 455 (edited 12-06-2000).]

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Skylark,<BR> I don't know if the BOP 10 bolt is any stronger than the chevy one but if it isn't I wouldn't put that much horsepower to it. What could happen is that you could break an axle and lose a wheel. My engine advice would be to make sure your heads are good for 500 horses as the '76 heads had smaller valves. They should be machineable for larger valves.<BR>Tomsriv<BR>71 Riv

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thankfully, buick axles are better designed than chevys, if you do break and axle, the wheel wont fall off, as it is held on by a pressed bearing carrier on the outside of the axle housing, not a stupid c clip. (the c is for crappy)<P>the 10 bolt will hold up surprisingly well with street tires, cause wheel slippage will prevent parts breakage. if you put slicks on, and switch to posi in the 10 bolt, you will break it if you drop the hammer too hard.<P>bassically, the best way to do a build up when you are low on dollars is start with engine and then drive easy until you have some money. then drive hard and use your savings to fix whatever you break. keep that up, and in a year or two, you will have replaced all the weak links in the car, and you will be ready to do some racing :)<P>allan<P>------------------<BR>allan<BR>--------------<BR>50 special, 455/th400<BR>64 stude gt hawk, 289/auto<BR>76 poncho GP, 400/th400

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Something else to keep in mind, as far as the BOP 10-bolt, is parts availability. My GS came with a 3.55 positrac, and I went through hell trying to get axle bearings and seals for it. Thank God for the local independent auto parts store. F-M had discontinued the bearing (I guess the GS/sportwagon axles are larger and require a bigger I.D. bearing), but he located a set for me in Kentucky--I guess there was a limited run of bearings produced a couple of years ago, and these were of the few which remained from that production run. Unfortunately they were $88 each. Same deal with the axle seals--slightly bigger I.D, discontinued, had to locate warehouse stock. Definitely be aware of weird parts differences and be willing to pay a premium for application-specific parts like I did. I am contemplating building a Chevy 12-bolt for the car since I plan on taking it to the track occasionally. I'd never forgive myself if I fragged the original rear on my GS. <BR> BTW, I know guys who put 450+ lb-ft of torque through 10-bolt rearends (on slicks). However, they are the 8.5" ring gear versions, not the 8.2" as used on earlier cars. Regardless, I think it's still just a matter of time before a 10-bolt grenades with hard use. Good luck!

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Thanks for all the help once again. I have done some searching for gears and posi carriers for the 8.2 BOP 10 bolt and have come up with zilch. This is the primary reason that I was considering a straight up 12 bolt swap. As much as I hate having chevy stuff where it doesn't belong, I'm not sure that I have much choice. Most of the boneyards in my neck of the woods don't go back past 80' so I'm screwed finding one that route. What is the ability to locate and swap the newer 8.5 BOP 10 bolt rear? I have found carriers and gears for this rear, at a lesser price. With the end swap is it better to go all out with the added strength of the chevy 12 or stick with a more original buick 8.5?<P>------------------<BR>67 Skylark 455

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You should have no problem finding a BOP 8.2 10bolt with 3:08-3:23 gears. Open rears are far more common. Keep looking and spread the word. Most GS,GTO,442's had 3:23 standard. If you want a posi. Get the Open rear and add a eaton,auburn posi unit. Bearings are not hard to find at all. If you go for the 8.5 rear Get one from a 71-72 olds, buick or Pontiac. It must be 2:73 or higher. Gears and posi units are available and came in all GM's to 81. But the 8.5 is Wider than the early 8.2 about 1 inch. 12bolts are Overrated a good 8.5 will easly hold up to 500hp with aftermarket axles. The last level would be the ford 9 inch. Be prepaired to spend over 1500 for a good ford or to rebuild a 12bolt Nearly every one has bad axles. Finally be carefull when buying a rear at the swapmeet. Once they have the money their gone and no help of refunds.<P>------------------<BR>Gatomon

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I don't mean to rain on your parade. Finding 500 HP out of the 455 is no "fairly easy" task. It involves a lot more that a cam and pistons. My engine is making about 425 "rear wheel" HP, which translates into 510 HP (figuring 20% loss). I am running an 8.5" 1970 rear with 3:64 gears from a TH400 with a 10" 3000 stall converter. I've used slicks with no problems at all, although I prefer to use "street" tires.<P>Bolting in a TA engine will only frustrate you, as the car is not ready for it and there will still be a lot of work left to do (read that as $$$$). <P>Making 500 HP involves exhaust system modifications (2.5" min, 3" recommended). Carb modifications, ignition system modifications, Stage 1 valves, head porting, intake manifold and exhaust manifold port matching. roller rocker arms (which mean different valve covers), chasis modifications. Now your going to go back and remodify the carb. This is not a project for those on a limited budget. Slicks alone are gonna set you back over $500.00 (the pure rubber inner tubes are $85.00 each)by the time you get them on the rims and secured (screwed to the rims).<P>Like I said, I don't mean to rain on your parade, BUT pistons and a cam do not a 500 HP engine make.<P>Another piece of advise, BE CAREFULL WHO YOU CHOOSE TO WORK ON YOUR 455. This is not a chivvy engine. They don't go together the same as a chivvy. I've seen reputable machine shops put the rods in backward, it's even been questioned in this forum. <P>Just an opinion of a guy who's been there, done that. As previously suggested, yank the engine and tear it down and see what you did to it. It's already broke, you can't do too much more damage. You should be able to rent an engine lift from a speed shop somewhere locally, I did the first time I yanked an engine. <P>Good luck and keep us all abreast of your progress. <P>------------------<BR>George C. Thomas<BR>70 GS 455 12.teens<BR>86 GN Low 13's/ high 12's

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I know that it's not just cam and pistons. I'm having the heads ported, valves done, etc. I've been told that the heads are by far the most important. I'm going to make sure that the engine dyno's at 500 hp off the flywheel. Whether or not I can do it on pump gas in another question. I have a new aluminum TA single plane manifold and 850 Holley Double Pump to compliment the package. I assume that's enough enough fuel to supply the beast, hopefully not too much. I'm not going totally cheap on this deal and I do very much realize the costs involved. Someone in town by me suggested a reputable shop and the guy just finished a 455 of his own so I would hope he's capable. Thanks for making sure I haven't missed anything crucial and hopefully I haven't. I'm going to leave this up to the professionals, as I don't really know what I'm doing. This is not a strip car by any means but I do want it to be fun to drive. I also an replacing the fuel pump and lines so that there's enough supply and a set of TA headers are also going to compliment the package running through 2.5" dual exhaust and Flowmasters. Is there anything else crucial I've missed?<BR>I also have HEI. I'm not interested in running slicks or tubbing the rear or anything like that just yet. We'll start with a posi and see where things go from there. If I've left any major performance features unchecked please to let me know. <P>Thundrr - what kind of track times do you run with that setup, ie slicks and gears? Also have you made any of mods to make it run that time, removing interior, etc? Your car seems similar to the performance goals I was going after. What compression do you use? Basically what are you running? I have recently come across a bit of finance and can finally afford for this beast to be treated properly. <p>[This message has been edited by 67 Skylark 455 (edited 12-09-2000).]

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My car is a complete restoration. Frame up. I use a '73 Qjet ( modified by myself via Doug Roe's book) on a B4B with a Holley electric fuel pump by the gas tank. I have roller rockers that are pushed up from a Hemi Killer cam. They sit on '72 heads with Stage 1 valves. I had Greg Gessler massage the heads and set up the valve springs. I use the copper head gaskets from TA. Compression is in the 10/10:25 range and I can use 94 octane gas. I use the Stinger S4 ignition system (including their distributor, as my old one was shot). Headers are from Poston. 2.5" club exhaust with a balance tube about 14' back from the collectors. Walker dynomax mufflers. A '70 Stage 1 4 speed rear, from a donor car, 3.64 gears. I haven't used the 9" slicks recently, primaraly I run the Hoozier Quick Time Pros. <P>My theory is to run the car exactly as I drive it on the street. Full bench seat interior, down to the floor mats in place, Steel GS rims, full size front tires, pump gas @ 3/4 of a tank, full exhaust, sway bars in place, a K&N 360* air cleaner in place, all belts in place. I havn't reinstalled the A/C unit yet. This is a column shifter car, so I just put it in drive and punch it. First gear shifts at 5800, second gear is my short fall so far, as I havn't got it up where it should be shifting. 2nd shifts at 4600. It goes through the traps at 110 in 12:teens (as seen in my signature).<P>With open headers, race gas, air cleaner removed and a 5800 2nd gear shift the car is clearly in the mid 11's. Maybe lower?? <P>It's really annoying to the Chivvy & Mopar guys when you don't even open the hood to prep the car at the track. I generally open the hood only to let it cool off a little after a run.<P>As an additional tip, I run a 4 core radiator and had problems keeping the car warm enough in the staging lanes (was running a 160* thermostat) so I went to a 170* stat and that helped. Yes, the car likes to be in the 170* range at launch and the 160* was just too cool for it. I use a thermal clutch stock fan (new thermal unit).<P>Hopefully, you didn't take my initial comments the wrong way. Your initial post kind of indicated that as a collage student, your funding was somewhat lacking and that your experience building motors was on the thin side. On your wish list, include some money for a decent set of tools as you will be needing them. lol<P>A sincere Good Luck!!!!!! <P>------------------<BR>George C. Thomas<BR>70 GS 455 12.teens<BR>86 GN Low 13's/ high 12's<p>[This message has been edited by Thundrr (edited 12-09-2000).]

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The problem with my car is not keeping it cool, it's keeping it from overheating and blowing coolant all over shopping center parking lots. It's really impressive when you pull up in a sweet old car and then blow coolant everywhere. I'm saving the body of my car for last just because I'd rather have fun driving it rather than just have it look mint from the outside, plus the paint's just faded not rusting. I was told that a frame off was not necessary as the frame and underbody are perfectly clean. My interior is about 75% restored, due to a blown heater core pumping coolant into the carpet, it's a nice touch. I'm going to put a high performance water pump on when I have the engine redone and I already have a monstrous 4 core. The only problem with that radiator is that it doesn't allow for room in the front for the stock clutch fan, so as of now I'm running a 4 blade flex, which on the highway or a longer trip to a show cools for sh*t, ie. shopping center experiences. Overheating has been by far the downfall of this car, even so much as it caused me to seize her up. How do I fit in a fan with some high rpm cooling power rather than just a simple flex? I surely can't afford a second over heat like this. So what's the magic trick to keeping a buford this size cool on a nice summer day? Also what temp of thermostat...150? Thundrr I didn't take any offense just wanted to let you know. I appreciate yours and everyone else's advice, as it's very helpful. I may be young but that doesn't necessarily mean that I'm a complete greenhorn. I've done most all of the everyday work on her myself but when it comes to headwork and grinding cranks I prefer to leave that up to the professionals. After all one doesn't just stumble upon a mostly restored 67 in WI for $3K, by accident. Thanks again to all.

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I know this may sound stupid, but check your water pump. The V6 pump fits the 300 at least, but you see, it spins the wrong direction. I forgot to mention that to you, but I had that problem. It would run OK on the highway, but it's come close to seizing up on me twice before I figured that out. Just a though

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