401 or 425

[bc65riv]

always thought i had a 401 in my 65 but previous owner says its a 425.

the numbers on the front of the block read 5H921163.

can anyone tell me what it is?

[RivNut]

It could be either but it's easy for you to find out for yourself. The number you listed is the VIN part of the engine number (does it match the VIN for your car?)

On the passenger's side of the engine - mirror image of where you found the 5H921163 number, you'll find a three digit number with a two letter code. Ignore the three numbers. The two letter code will tell you year and displacement. Use the following to tell you what you have: K=64, L=65, M=66; T=401, W=425. There could be letters other than T or W, but those would be for two barrel, low compression, or export engines. The attachment will help you locate where the numbers are. This illustration comes from a '66 chassis manual so it identifies a '66 engine.

Ed

[bc65riv]

thanx ed---yes numbers match and LT means 65 401

[RivNut]

28~K of the 35~K Rivieras built in '65 came equipped with the 401. So about 4 out of every 5 cars are 401's. Does your car have the original breather on it? If the breather decal is correct, it should say Wildcat 445 on it. The 445 stands for the lb. ft of torque the engine develops.

No matter whether it's a 401 or a 425, the bigger thing is that it's a numbers matching car

Ed

[lrlforfun]

OK Riviera People: I guess that if I were paying 75K for the yummiest 65 Riv GS on the planet it might make a difference if it were the original engine, otherwise "original matching numbers" only mean that. It doesen't make it a better car. This to me is ridiculous mythology that makes life a much rockier road in this hobby of ours.

A 65 Riviera is still a Riviera even if it has a 6 in it! And for the record, my 65 Riviera has a 64 engine in it. When the original engine started blowing by so bad out the breather I found a smashed 64 Riviera in the junkyard and proceeded to swap out the engine and many other parts. My wish for everybody out there is that........... I wish you can enjoy your collector car with what ever motor it has in it as much as I have enjoyed my car because I sure enjoyed it and will continue to enjoy it.

One other numbers matching fact that you can go to the bank with. Saying that the numbers match on a car is almost identical to spending somebody else's money or pointing out the faults on another person's whatever. It's sooooooooo easy to do. Mitch

[CTX-SLPR]

OK Riviera People: I guess that if I were paying 75K for the yummiest 65 Riv GS on the planet it might make a difference if it were the original engine, otherwise "original matching numbers" only mean that. It doesen't make it a better car. This to me is ridiculous mythology that makes life a much rockier road in this hobby of ours.

A 65 Riviera is still a Riviera even if it has a 6 in it! And for the record, my 65 Riviera has a 64 engine in it. When the original engine started blowing by so bad out the breather I found a smashed 64 Riviera in the junkyard and proceeded to swap out the engine and many other parts. My wish for everybody out there is that........... I wish you can enjoy your collector car with what ever motor it has in it as much as I have enjoyed my car because I sure enjoyed it and will continue to enjoy it.

One other numbers matching fact that you can go to the bank with. Saying that the numbers match on a car is almost identical to spending somebody else's money or pointing out the faults on another person's whatever. It's sooooooooo easy to do. Mitch

My '64 does have a V6 in it... though I do have the original 425 on a stand next to it.

[Guest riv63gs]

OK Riviera People: I guess that if I were paying 75K for the yummiest 65 Riv GS on the planet it might make a difference if it were the original engine, otherwise "original matching numbers" only mean that. It doesen't make it a better car. This to me is ridiculous mythology that makes life a much rockier road in this hobby of ours.

A 65 Riviera is still a Riviera even if it has a 6 in it! And for the record, my 65 Riviera has a 64 engine in it. When the original engine started blowing by so bad out the breather I found a smashed 64 Riviera in the junkyard and proceeded to swap out the engine and many other parts. My wish for everybody out there is that........... I wish you can enjoy your collector car with what ever motor it has in it as much as I have enjoyed my car because I sure enjoyed it and will continue to enjoy it.

One other numbers matching fact that you can go to the bank with. Saying that the numbers match on a car is almost identical to spending somebody else's money or pointing out the faults on another person's whatever. It's sooooooooo easy to do. Mitch

Original cars are only original once. No mythology about that. Most of our cars have been modified/updated in one way or another. Mine included, my numbers don't match. It's been resprayed and has a new interior. I prefer to keep as original looking as possible. It's the owner's prerogative. I'm easy, I love them all; bone stock originals, customs, trailer queens, hot rods, exotics, tuners...etc. I agree that the most important thing is to enjoy it. Enjoy the crap out of it and pass it on. Gerry

[Guest Gee_Rydes]

2 more cents worth...

If you are keeping the car and you enjoy ownership, all the comments about "other than original" engines are right on. Do what you want and enjoy it.

However, any of us that have ever sold one will tell you that one of the first questions is "numbers match"? Now that may only be a roadblock to somebody more concerned with market value than ownership value.

If it still has a Nailhead, the value is still pretty good and really has the biggest impact on the GS models in my experience and maybe some on the 425 single barrels and LX non GS's. If a completely different engine is in the car (other than a Nail), it has much more of an impact. Similar to repainting a Riv a different color but one still offered in that year. That usually passes better than a non year (or generation) correct color. The further you get from stock, the more it has an impact.

Hell, mine doesn't match, but I am not going stock Resto so I don't think it will matter much.

[Guest jonly]

stick the matching numbered one in your shed and drive the 425?

[lrlforfun]

OK Riviera people: As a kid I was a spoiled brat. One example of my behavior was that I'd scream if my Mother brought home any kind of groceries that weren't brand names. Today it's a different story. My wife buys what ever she feels is her good deal..........which is a combination of things like price, quality and past experience. I can guarantee you that it is very happy!

Growing up with GM cars was similar. There were no 6-cylinders, no sticks and not even a used car for many years. It had to be a Buick with the exception of my Father's company cars which eventually were Buicks.

As a car man through and through, especially being a young guy when these beloved rides were in daily service, we NEVER NEVER EVER even dreamed of this matching numbers mythological suggestion. What difference could it possibly make? If a car was cool, it was cool, period. Mitch