84TAProject

Okay, I just got ahold of a 1" carb spacer for a quadrajet. I have this on the t/a in the signiture. It is an open spacer on a ZZ4 manifold. I went for the ZZ4 over the RPM manifold for EGR, pulled the old intake off and realized I dont even have EGR passages in the heads. Anyways, saying I add this spacer, how will it change the power curve? Im thinking hurting a little down low but helping up top. Ive got a cowl hood, so clearence isnt a huge issue for me. One concern, if I lay the 4 hole gasket over the spacer, i can see quite a bit of metal through the primary holes. I dont think a spacer (its a mr gasket) would keep anything from opening right? Also, for a bottom gasket, should I keep the big thick one I have at the bottom or use the 2 4 holes that came with the spacer. In my mind, using that 4 hole one at the bottom will restrict air, as its 4 holes, and to go from open through 4 holes to dual plane again just makes no sense to me

NTChrist

I don't have a lot of hands-on experience with spacers, but I'm pretty sure you're right.
An open spacer, like yours, will help with higher-rpm breathing. It will also increase the plenum volume, which can be beneficial if your carb is too small for your motor. This probably doesn't apply to you.
A 4 hole spacer increases torque, as far as I know.

Are you sure that you didn't buy a square bore carb spacer? You probably shouldn't be seeing any spacer through the gasket.

I agree with your theory about the bottom gasket. I'd recommend taking an exacto knife to the gasket, and matching it to your spacer.

84TAProject

Im sure its a spreadbore carb, the package says quadrajet and thermoquad. And its that weird staggered type thing. It looks like it should work fine, just the gasket lines up funny. Ill try to get pics up.

Jester

Assuming you don't open up any vacuum leaks or run out of hood space, a 1" spacer of any kind will never hurt. Go for it.

IHI

iTrader: (1)

I was running an rpm manifold with a 1" aluminum open spacer and I thought it ran pretty good. Decided to try a poly 1" 4 hole, WOW, big seat of the pants difference. Definately don't want gasket material hanging out for no reason, it waould just give the gas a place to "puddle" up.

Mark W. Winning

On my Firebird, I picked up some throttle responce by adding a 4 hole spacer to the intake. I later learned the 4 hole spacer increases the signal to the carb. I do not know how much top end power this spacer would add. The single hole spacer would be the one for the top end increase, but my soften the bottom a bit. I say may, as a single hole spacer did not seem to botter my car any when I tried it.

NTChrist

I'm planning on running a 4776 Holley 600cfm double pumper on my healthy-ish 350.
I think my case would benefit from a single hole spacer, right? Increase the plenum volume? Kinda like a single plane, take some of the load off of the carb?