Does anyone know where or how I can get the dimensions for a 1" carb spacer? I want to build a couple for a holley 650 squarebore. I want one with the 4 holes instead of 1 big hole. I'll be cutting it out of aluminum on a water jet. thanx for any help.

Can't measure a gasket ???

They are available already from the aftermarket. And they're often made from a plastic material that does a MUCH better job keeping engine heat from conducting up into the carb than aluminum does (aluminum conducts heat like crazy).

I was looking for a more accurate measurement. Plus need the holes and everything to be just right in order for me to put them in the computer. And whats the differnce between putting a carb on an aluminum intake or a carb spacer. They both conduct heat. Beside I thought the gaskets would act as insulators.

True, using an aluminum spacer is no different than putting it directly on the intake. The gaskets help some but it's like the difference between having R-12 insulation in your attic and R-45 insulation. If given the choice, which would your rather have on a hot 100* day with the sun baking down?

I beleive most 4-hole Holley gaskets use a hole diameter equal to or slightly larger than the throttle bore diameter of the carb. For anything 650-800 CFM Holley uses 1-11/16" throttle bores. 850s use a slightly arger 1-3/4" throttle bore. So somewhere around 1-3/4" would be what I'd use for computer modeling purposes.