I have a chance to get a '75 Firebird with a 350 ci engine as a cheap parts car. It would supply parts for a '77 Firebird Formula with a 400 sbc (stock). Does anyone know if the stock 350 out of a 75 Firebird uses the sbc or the bop bolt pattern? Also, I assume the rear end would be compatible?

Thanks,
Jay

The rear will probably bolt in. I'm not sure, but I think they still used Pontiac motors in '75. You'll know it isn't a Chevy as soon as you open the hood.

GL

I believe it was the BOP pattern.

First, The 1975 and the 1977 Firebirds both came stock with Pontiac engines. They never installed a SBC 400 in a 1977 Firebird Formula, It was a Pontiac engine.

So by that account, They would be BOP bolt patterns.
If someone did install a Chevy engine in either vehicle, Then it could be the SBC pattern, but that means they swapped the engine and the trans.

quote Originally posted by Oreif: First, The 1975 and the 1977 Firebirds both came stock with Pontiac engines. They never installed a SBC 400 in a 1977 Firebird Formula, It was a Pontiac engine. So by that account, They would be BOP bolt patterns. If someone did install a Chevy engine in either vehicle, Then it could be the SBC pattern, but that means they swapped the engine and the trans.

What he said.
But be sure to check the engine. As old as they are it's very common to find one that's had a Chevy motor put in it somewhere down the line. The quickest and easiest way to ID a Pontiac vs. a Chevy (if you aren't familiar with them) is to look at the distributor. On a Chevy, the distributor goes through the intake manifold. On a Pontiac, it doesn't, it goes directly into the block at the valley pan. (similar idea to the Edelbrock RPM Air Gap manifolds). Since engines can be painted any color and if you don't know what a Pontiac or Chevy looks like, that's a good fool-proof way to check.

Ok, maybe I am proving my ignorance here, but I have seen this term used before and have nooo idea what it means, so I will ask:

What does BOP mean???

Eric

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Used is such a harsh term. . . I perfer "Previously obsessed over" ;)

88 4 cyl 5 speed: All show and no go
86 SE V-6 Turbo 4 speed: All go and no show

quote Originally posted by Racingman24: Ok, maybe I am proving my ignorance here, but I have seen this term used before and have nooo idea what it means, so I will ask: What does BOP mean??? Eric

Buick, Olds, Pontiac

^^^ What he said...

BOP was a standard Bolt Pattern for the bellhousing of the tranny to match up to the block of the engine...
Buick, Olds and Pontiac all shared the same pattern, and Chevy had a different pattern.

Thanks guys, +'s for both of you.