Curious as to how we know an olds engine is particular to a certain car. For instance, is the VIN stamped onto the block or heads at all or did they just stamp a code specific to the engine and you only will know if the block came from a specific year and/or date? Can you trace an olds engine to any one specific car? If I remember right you can only tell what year the engine was cast and made, there are no indications it came from a particular car, right?

Does anyone know what other GM mfg's did as well? I'm looking at a '66 GTO tomorrow and want to know about that motor as well. Would I be able to tell it's for a specific VIN or specific model or will I just be able to verify it is a 389 that was manufactured in a certain year and that's it?

 

The vin is stamped on the block and its the only way to know if its original to a certain car.... that I know of. You can't really trace an engine to a car...unless you have that car to compare the vin on the dash....and other places.

 

And IIRC they started doing this in 1968 and newer.
Scot

 

Under the hood, the block and transmission are the only two items that have the VIN deriviative stamped into them such that you would know they are original to the car. Things that go on the block (heads, intake, exhaust manifolds, carb, alternator, water pump, starter, distributor) don't have anything stamped into them that make them unique to a particular car, but their part numbers (either stamped or cast into them) as they relate to model series, and their manufacture dates can give you an idea if they were original, or not, to the car. A part with a correct part number to the car, but with a date code that is after the build date of the car, is obviously not original to the car.

Randy C.

 

Correct. Prior to the 1968 model year there was an engine unit number stamped on one head, but that can only be traced to the car's VIN if you have the Protect-O-Plate. Of course, all that "proves" is that the one head is original.

 

So, what we are saying is that prior to 1968, there were no VIN's stamped into anything other than the door VIN plate to match the motor or tranny to the exact car, correct?

Now, we get to the point of, what am I going to look for to know if the motor from this '66 GTO matches the car to the best of ability. Probably have to look at the cast number and determine if the date is prior to and that is about all you can do right? Anyone know where to look for it on a 389 Pontiac motor? Are the heads stamped and where do I look there? I assume all Muncie's are the same, which is what this has in it, so I can decipher that I think.

 

The information in this thread applies to Oldsmobiles. I know for a fact that Chevy blocks used a VIN derivative prior to the 1968 model year. No clue on Pontiacs. You might want to try a Pontiac site for accurate info.

 

Pontiac, like Olds, did not start putting the VIN deriviative on engine blocks until the '68 production year There is an engine production number and an engine manifest code on the passenger side front of the block, on a machined pad, but that's it for '67 and before.

A couple of books to check out: (1) Pontiac GTO Restoration Guide 1964-1970 by Paul Zazarine and Chuck Roberts, and the Motorbooks International GTO Red Book for '64-'74 GTOs, by Peter C. Sessler. The restoration guide is especially good at showing you what markings to look for, not only on the block, but other engine components and the transmission as well.

Randy C.