Holley 390cfm 4 barrel is it to small for my car?

I'm dropping a 283 in my Hudson it is backed by a th 400 trans. The motor is said to be .030 over and has an edelbrock performer intake and a hei distributer as far as I know it's a stock cam and heads will be running the stock exhaust manifolds and 2 1/2 inch dual exhaust with turbo mufflers the motor is out of a 1965 Chevelle I just want to know if this will be too small of a carb to run on this motor it's a Holley 390cfm 4 barrel vacume advance. Of would I be better off with a Rochester 2 barrel I can get the rebuild kit for the Holley for 33 and the 2 barrel for pretty much the same price that's supposed to be good to go.

 

Use the Holley. Good street combo with the rest of the engine. A tad bigger wouldn't hurt, but wouldn't run any better, just maybe a bit more power at higher revs, not necessary in a cruiser.

 

i bet this carb is small
http://www.youtube.com/watch?v=UGClulA96K8

 

keep the holley

 

I raced an asphalt latemodel and we had to run a 390 holley per the rules and it worked fine on a 600 hp 358 c.i. Ford engine should work fine on the 283

 

Ok I was worried because all the cfm calculators I used said 450-550

 

Keep the 390, tell everyone it's an 850.

 

390 will be fine

 

I was worried when you said it was a "vacume advance" model.....but it will be fine with vacuum secondaries too

 

Yes vacuum secondaries had a brain fart I guess lol

 

On a near stock 283, the 390 CFM Holley sounds about perfect to me. Go for it.
Mart3406
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Used one for yrs on a mild 283 in my 57. Ran like a champ and good economy too.

Use it imo.

Rat

 

A 600 cfm vac secondary would be my first choice but a 390 vac. sec. will be just fine. My basic calculation is 2(cid)(.75) where .75 is efficiency. By this I get 424.5 cfm. You aren't missing a whole lot from 390 to there so your carb will work to it's full capacity and you will get good economy too.

If your engine was ported, headers, intake, etc. I would bump the efficiency up but a mostly stock engine gets .75 as a starting point. Case in point is my flathead 2(239)(.75)= 358.5. Add a cam intake and .040 bore and a 390 carb is just about perfect, just like for yours.

 

If you have it, run it. The 4GCs and WCFBs that Chevrolet put on the 283 power pack engines didn't flow any more than that. People tend to overcarburate just as much as they tend to overcam....maybe more, since it's easier to change the carburetor. Don't pick a carb that's going to work better than the 390 one tenth of one percent of the total time you're driving it.

 

I bet it will run fine, I'd use it

Buckle

 

I use one on my 84 El Camino 305/700R4 and it works just fine and gets decent MPG.

 

My calculations say you already have a 390 so instead of spending cash on a 450-550 I'd run what ya got. 450-550 is not that big of a step up.