Carb Spacers

Looking to purchase a Wood-Fiber Laminate carb spacer. There is two I'm looking at but not sure which is the better one. The first one is a 4 hole spacer and the other is a open spacer. I have a Eddy Performer RPM intake with a Eddy 750 Performer carb. Has anyone tried one or both ?

With the 4 hole you will gain some torque down low, and better throttle response, with the open you wil have more plenum volume, so more power high, but it will be lazier down low.

see above
And the Edelbrock rpm is a dual plane intake, geared more towards low-end & mid-range I believe

I've tried both but in phenolic, not wood fiber. Results will depend on the rest of your setup and driving habits/conditions. The only way to judge accurately is to run without any, then add/swap them in to feel the results. Remember that some minor carb tweaking is in order to maximize each change. For me, the open spacer on my 440 gave no softening of the bottom end simply an upward shift in the rpm range where the torque seemed to start to hit, by maybe a few hundred RPMs. On an 'enhanced' big-block I don't see it as a detriment..The extra pickup from the mid-range up was indeed noticeable..I believe the 'kills your low end' is a myth unless the engine is not set up to take advantage of the slight increase in plenum (a stock engine for example). The four hole made it easier to spin the tires immediately off idle but didn't feel really different much beyond that compared to the intake by itself. Again, these were my own results but I'm sticking with the open spacer...only my opinion of course. Check them both out for sure

I’d be wary of running a 4 hole on an RPM, as that intake has no physical support for the center part of the spacer.

I have a pic somewhere of what happened to mine after a backfire.

Edit: found it...