I have a little more time on my hands as I got laid off for the slow season. Anyways, as you know I've been designing a cast aluminum intake. Now I want to narrow down the carbs a bit. I want to use a 4 bbl, and I'm thinking a Holley (390 cfm?). What I'm looking for is a gasket so I can lay out the top of the intake. Question is, if I lay it out with a gasket for the holley, will other holley carbs fit later, say up to 500 cfm?

So far the 225 is completely stock, but later I want to install larger valves, pistons and cam. When I get the intake done, I will be installing headers. Would I better off designing for a 500 cfm holley set up now or will a 390 cfm be just as good over all?

_________________
Slant Six... out of the ordinary - just like me!

all the holley model 4150 and 4160 carbs have the same base dimensions and bolt pattern. The only difference (in the baseplate) is the throttle bore diameter.

The 390 cfm carb you're talking about is a model 4160. They make these carbs in sizes from 390 to 1050 cfm.

If you are getting a gasket for 'patterning' there are only 3 for the Holley 4150/4160 series:

390-500-ish with the smaller bores (4 smaller holes in squarebore pattern)
500+ with the larger holes (4 large holes in square bore pattern)
or like the Hpak/etc...

open plenum gasket with one larger square hole in the middle....

All Holley rebuild kits come with one of each of these, or you can buy them separately as needed.

-D.Idiot

Thanks. So I can use a pattern for the 4160. Then if I want bigger then at most I should only have to make the throttle bore diameter larger.

Thanks again.

_________________
Slant Six... out of the ordinary - just like me!