Need mechanical info on 1972 GP drivetrain
 

I'm in need of getting a vehicle up and moving reliably under it's own power. The drivetrain is stock 1972 Grand Prix powered by a big block. Right now the carb is messed up. I don't know if it's worth trying to rebuild the carb or just buy a new one. One of the reasons I know the current carb is messed up is one of the butterfly's is messed up. The big long single butterfly at the front of the carb. It's disconnected from the linkages and if I try to connect it to the linkages, it rotates in the opposite direction of the linkages. (Prolly why it was disconnected)
If there are any experts out there in 72 big blocks, I'd appreciate hearing from you and getting some advice on how to get this beast moving once again.

If a replacement carb is the way to go, any recommendations on where to get it? If rebuild, where to source the rebuild kit?

Thanks,
Dan McCann

It's been my experience that a carb in need of help as yours is.. is best left to a professional. Ask around your area for the carb place in the area. Usually there's one place that stands out.

When I needed a hand with one.. I went to that place and the guy knew in seconds what was wrong and had me out of there for $10 in under 10 minutes. :shock:

What kind of carburator is it, Rochester? There is a good book by Doug Roe on Rochester Quadrajets that goes into detail about how the carb functions and how to disassemble/assemble them. It also talks about others besides the quadrajet. I used it to rebuild mine. When I first read some of the book it was hard to understand, but once I got the carb off and was able to see the parts in person it helped me to better understand how everything works together. If you are mechanically inclined it shouldn't be too difficult.

I also know of a couple good places to have them rebuilt if you don't want to tackle it.

pontiac engine have no big block there all the same size from 326 to 455

He's right, although they weren't considered small blocks either. They ran in between sb and bb in size.

yeah 326 heads on a 455 for compression or the other way around for flow

I'll have to verify....I believe it's a 455. If I can this weekend I'll pull the carb and see what make it is. Last I worked with a carb was an 82 Buick with a computer controlled Quadrajet. An odd bird for sure.

I am mechanically inclined, so I may try the rebuild myself at first. If I fail, then I'll see about the pros. I know of nobody that stands out locally for rebuilding carbs.

Dan McCann
Pittsburgh, PA