Okay, I am in the market for a new carb and I think I want to get the same model as the one I currently have. I know it's a Holly double pump and I was told it is a 750 CFM. Will it really matter if I get another one that is less than 750 CFM? also, will it be better to go higher in CFM? I am looking at a [IMG][/IMG]650 CFM Holly DP.....just wanna make sure I get the right one.....you thoughts?

 

It depends on what you have for a motor. I just went thru some carb issues. I just bought a Proform 950 and I'm really happy with it. Some people don't like them but so far so good for me. I had an Edelbrock on it and I was not impressed.

 

Holy cow, I think that's the largest picture I've ever seen of a carb here!

I think you're better off going a bit too small, than going too large. But without some specs on your motor it's hard to say. It takes quite a motor to handle either the 750 DP, or the 650 DP Holleys, and most people's cars would be better served with a vacuum secondary four barrel, than a mechanical secondary with two accelerator pumps. If you're talking a vacuum secondary carb, then a little large works out, as the secondaries wont open until the engine demand and vacuum is there.

 

The 750 was on the car when I got it and judging by all the race parts used on the car (evidence of NOS, battery relocation etc.) I think the motor is built quite well and has a solid lift cam in it. It runs good with the 750 so I ended up getting an 800 with the same design (DP, mech secondary's etc.) we'll see I guess....I know initial tuning may be a bit tricky but again...we'll see=D

 

Looks like its seen some back fires. Gotta love the Channel Locks for tightening the carb stud. I would run a 650. The only thing I don't like about just about every vac secondary carb is the lack of jets on the sec. side. How high do you rev it? Thats has a lot to do with CFM as well. Honstly a well tuned 650 will be fine on the street. Try a street avenger. 90% of cars out there are over carbed.

 

Even when I raced my Camaro, I still ran a vacuum sec. 750 Holley on my 427. I still have a 750 Holley with vacuum secondaries on it, and it's plenty of carb for the big block. Can't imagine ever needing a 800cfm double pumper.

 

Well damn.....hope I didn't waste my money! It was either an 800 CFM DP for less than $200 or a 650 CFM DP with elec chock for around $500....both were mech secondary models....the one I got was rebuilt and the other one was "new" so.....we'll see. Fingers crossed!

 

*choke*

 

I only say " fingers crossed" because I am un sure of the motor's internals/requirements. It is supposed to be a 355 with a solid lift cam (specs unknown) as well as upgraded rods and pistons(unknown comp ratio). It is also supposed to have a 750 CFM Holly DP that I hope I was able to replace adequately.

 

Lots of unknowns there, and could really affect carb choices dramatically. I sure understand trying to save a buck (I always do too!) but not sure I'd be so quick to jump on a carb that large, regardless of what's inside a +.030" 350.