Carb spacer for my setup?
I am installing a 600cfm Holley 4160 on my 302 with a stock Ford cast iron 4 barrel intake manifold. The engine is stock, so 4800rpm power peak and roughly 5200rpm redline. I do have long-tube headers and a 2" dual exhaust.
I've heard that the main benefit of a carb spacer is increasing plenum volume, which increases higher rpm power at the expense of lower RPMs. I know that they can also keep the carb cooler, especially if you get a plastic one.
Seeing as my engine won't be revving especially high, and that I have an iron intake (which doesn't conduct heat as much as aluminum, so shouldn't heat the carb as much?) how much benefit would I get from a carb spacer? And should I get one of the open ones, or one that has 4 holes (which should match up with the 4 holes in the Ford intake)?