So here is the problem. I was going to rebuild my my 289 so I bought a holley 570cfm streetavenger carb. with auto choke. ($360). Stupid of me to buy it before the engine was built. Anyways I have the carb still in the box never even seen the garage just sitting in my room. I want to sell it and get a 650 cfm because thats what is recommended by for for their crate 302 engines. So is there a way to make my 570 work or someone have a 650 (new) want to trade. Even better if someone wants to buy it for what I did for the same price because I will loose money on ebay. Help me out guys. thanks

 

can you return it?

 

no it has been past the 30! days I thought it was 90!

 

Raise hell, If i can return a painted waterpump then you can return a new carburetor.

 

You may want to try it on the new engine. It certainly won't hurt anything. You may even have a way to alter that carb to a 650. Do some research.

 

the good thing about hollys you can always change the jets

 

I've got the same 570 strret avenger on my warm 289. It really is a sweet carb, once the correct jets are in. In fact, I think you would find the only area where the 650 would be any better is at max revs.
The 570 will give better throttle response throughout the rest of the rev range. Also, the street avenger has quick change secondary springs, and fuel metering block, and it flow is underated. I say give it a go, I dounbt you will be dissapointed.
http://holley.com/types.asp?type=7

 

so I would have to change the jets to make it give enough, will it work fine you think if i leave it stock? I know about engines but carbs are a little down the road...alot to understand! I dont really want to change anything on it

 

Changing jets on a carb is not modifying it. its simply tuning. I didn't do mine, I got a dyno tune, and had the air/fuel ration mapped, and the jets changed to bring everything in line. Im told its a very simple thing to do, but make sure you find a tuner with holley experience.