So as I am slowly restoring my bird I am finding some odd things out about it. The body tag says it is a 1967 car. The engine is a 1968 pontiac 428. The carb is a '72 Rochester 4bbl. My rear axle ratio is 2.56, and I have a 4-speed manual trans. The rear end quarters have side marker lights...indicating that someone has put in a '68 rear end...right? I have little pivoting windows (pardon my primitive wording), which are only on '67s (I think). I'm having a hard time figuring out what the heck this car actually is! Seems at this point to be a Frankenstein car to me. If someone has nothing better to do, and can help me figure this out, it would be helpful. Ordering parts becomes a pain because I have to always figure out what year I'm working with to make sure it fits.

I would say yes, somebody put '68 rear quarters on your car.

According to the Supplimental Service Manual for the '67 Firebirds, NO manual shift car should have come with a 2.56 rear.

So why would someone put a 2.56 rear end in with a 428 engine? Seems backwards to me....Oh well. Something I can change out later I guess.

Get the PHS documentation so you can find out whats left original on it...as far as ordering, sounds like you have a '67 with '68 quarters...easily remedied. If the rear end is original, then it probably started life as a 326 with a ST300 2 speed tranny...just guessing off the top of my head though.

Somebody wanted a highway cruiser. Some previous owner did the same thing to my car, changed the factory 3.08 to a 2.56. And I am talking about swapping out the entire axle - not just the gears.

So I put a HD 4 pinion posi 3.55 axle in that I found instead.

my 69 came with 2.56 stock rear....it was a 350...but with the 400 its great hwy cruiser...getting a whopping 14 mpg! LOL, so Im glad I have the 2.56....

PHS documentation?

Pontiac Historical Society

They wanted a nice highway cruiser that wouldn't be total dog off the line.

There was a thread on this site about a year ago about a Frankenstein car like this. Did you purchase it recently? My guess is that you have the same car that was discussed.

If I'm thinking of the same one, didn't it have mixed years between the VIN, Body Tag, and conflicting parts?

Yes. There were pictures too, I think? Almost like two cars welded together...

I'd be estatic with 14 mpg

Is the VIN inside the door jam or on the upper dash? 67 was the only year they attached the VIN inside the door jam on any year Firebird. I would still purchase a PHS to clarify what the car should have vs. what it currently does have.

I'll have to find that post. Interesting. Well I'm not going after a parts matching or all original car, so I'm going to work with what I've got I guess. Still a great car, sans the Frankenstein-esk nature of it all. Thanks everyone!

This one?
https://firstgenfirebird.org/forums/ubbth...true#Post173614

That's not my car from reading the post, unless he replaced everything all over again, but sounds like he wanted to get it back towards original. Will the PHA tell me, based on the VIN, what components were in my exact car (i.e. engine, trans, rear end etc.)?

Yes, the PHS will tell you exactly what the car was originally equipped with from the factory - including all drive train components.

I'll check after work. I haven't treied running it through the VIN decoder on this website either. Maybe that will give me a glimpse into this car's history.

It will at least get you started with some of the basic information. Plus, it is a free resource. However, the PHS is the best source of information for verifying the A-Z build of the vehicle.

I get 17 mpg with mine.

Managed 16 but its hard with gas pedal between 470hp and 3.42's.