Just wanted to get some opinions on the size carb I should be running on my new setup.

I have a 425 BBO, compression should be somewhere around the stock 10:1 as it was a factory 4bbl. Has been rebuilt with .030 over pistons. Has an edelbrock performer manifold, Erson TQ40 cam (504 lift 220/228 duration at .050), stock A heads and hedman 1 3/4 primary headers.

Looking to get a new carb and in between whether it should be a 750 or 850. I do plan on doing a full build on this motor with aluminum heads eventually and i know the 850 would help then. But right now would an 850cfm with vacuum secondaries be too much? Any help is appreciated.

Tim

 

800 quadrajet will work.camshaft is more of a good street grind . size factor is more how you drive it.carburetor with smaller primary's ,are more sensitive at part throttle.bigger carburators can make more top end power but could trade off lower tq at rpms where you drive at.for a street and strip carburetor I prefer quadrajet you get kind of both , small triple booster primarys and big secondarys. There are more complicated to tune but today there is a lot more info out there on how to do it. I know not everyone here agrees with me.I drive engine in cars ,not on dyno numbers.if you are wanting a strip only car .you wont care about low end tq, idle quality,part throttle responce.the launch RPM is uesally way past 3000 rpm anyways.
If you are a person that just want to buy a carb and just put it on .go consertive on size you be happier with it.if you got fat wallet go to guy that owns a dyno buy a carburator off him and let him tune it for you he will make sure it the right size and works.