What size carb do I need.
 

On my current motor I am using a modified 850 holley that flows about 930+ cfm. Its mounted on a 454 with a 177 blower

If I re jet it would this carb work on a 502 with a 250 blower ???

Re: What size carb do I need.
 

I would sure consider a dual 750 carb setup on that config. But what you have will most likely work, just watch out closely for a lean condition.

Re: What size carb do I need.
 

I ran a Nickerson 1050 on my B&M 250/468 CI motor. Dean had it dialed in perfect. You would have no problem selling your 850 carb to a 502 or 540 owner.

Re: What size carb do I need.
 

When I set up a 509 with 8 71 I ran dual 800's. When I where questioning if it had enough carb. I was told to check for vacuum at the at the top of the blower/ bottom of the carbs. If there is vacuum need more carb.

Re: What size carb do I need.
 

That's probably the best dam*ed info that I've heard regarding blower carbs and the need to not blower reference! I'm runnin' a 420 that everone said I'd have to blower reference my 750's. Not even close! Zero vacuum at WOT. Great explanation man!