Originally Posted by bonny99
Does anybody know if a 1977 rochester 4 barrel will work on a 1974 350?
Yes, if it has a 4 barrel manifold you can make it work, or you can trade the core to a qualified rebuilder who can set it up for your specific engine application. My local carb shop charges around $140 to rebuild a Qjet, with base and air filter gaskets and a warranty. I can't buy the parts and do it myself any cheaper than they can.
And just for what it is worth, the Pontiac community doesn't refer to a Pontiac V8 as a big block. The terms big block and small block are generally used to distinguish between different engine families of the same manufacturer, such as Ford, Buick, or Chevrolet. All the V8s made by Pontiac Motor Division from 1955-1979 had very similar block dimensions, except for the 301 and 265 which were short deck blocks, so they were slightly shorter, but definitely not a "small block". For the most part, when those of us in the Pontiac community
use the generic term big block and small block, we are referring to Chevrolet engines, which are definitely different than Pontiac engines. Yes, a Pontiac block is bigger than a Chevrolet small block, but not as large as a Chevrolet big block.
When trying to identify a specific engine in a car of this era that could have had an engine from almost any one of GM'* divisions in it, it is too vague to simply classify it as a "big block" and can be misleading to someone who may think you know the difference and you have verified that you actually have a Chevrolet big block retrofitted into your car.
Having said that, there is not one generic carb tune for large engines and another generic carb tune for small engines. Qjets were used on a very wide variety of engines and each engine got a Qjet that was tuned specifically for that model of engine
If the carb you have that you want to use is in good shape and not leaking, I'd say stick it on there and see how it runs, you will know in short order if it will do what you want it to do.
Maybe this comment was limited to the 1977 model, in which case it is understandable, but still inaccurate...
Originally Posted by clm2112
the Pontiac 400 motor, which was never intended to be a hot rod motor
I'm not sure what you would classify as a performance engine then. Sounds like you aren't familiar with the Ram Air (especially 4!) engines, and probably the history of Pontiac V8 engines in general if you really believe that. In the late fifties and early sixties the really serious hot rodders knew that whatever sort of vehicle they were building, if they wanted to go really fast, they would swap in a Pontiac V8. The 400 replaced the 389 in 1967 for the express purpose of making more power in the muscle car era, specifically for the GTO and the new Firebird . Google "Pontiac Ram Air IV" or check out the Street
sections on Performance Years Forum to find plenty of people that get very respectable power numbers and verifiable track times using classic Pontiac V8s. It'* just that they do it by making wicked torque and
horsepower across their entire power band, instead of just concentrating on peak top end horsepower.