[JasonL]

hello all, finally got my motor together and need to use a carb spacer. I have a 355, 9:1cr, 268HE cam, 492 heads, performer intake. Holley 670 vac sec carb. I need a spacer and I have a open one (1"). Is this ok, or should i get a 4 hole one. I can go to a 1/2" also, just need to clear the linkage.

Motor

[hcompton]

The open spacer will effect the intakes dual plane design. But it may effect for the better depending on the setup. I would give the open 1" spacer a try and if that does not provide good low end power move to a four hole spacer for added punch down low.

It wont hurt anything and you can use the same type so you dont have to change the linkage if you want to swap the spacer. For the four hole type later on. A lot of people run open spacers on dual plane intakes as it will amke you intake seem bigger to the engine than it is.

hope this helps.

[JasonL]

Guess i will get a 4 hole one. I am looking to keep as much low end as possible. i would run no spacer if the carb linkage did not hit the egr part of the intake. I am thinking of just getting a 1/2" one. It will give me plenty of room and hopefully not kill the low end.

[poncho62]

Cant you just grind off the linkage or EGR a bit where it is hitting?

[my87Z]

Personally I would run the 1" spacer, you already picked the smaller runner Performer intake instead of the performer rpm intake (I would have gone with the rpm), but it wont make that much of difference. Like someone mentioned before it will act as if you had slightly larger runners, you still have the divider plenum so the their wont be any swirling and and turbulance will still be fine.


I actually ran a 383, ment for strip/strip with a performer rpm with a 1" spacer, I had the plenum divider milled down 1/2" (got the idea from a dyno show). I had that 383 dyno'd with both a victor jr and this modified rpm intake, the vic jr made alittle more high end hp but the modified rpm made considerably more tq.