Just putting a mechanical pump on my car and the parts store didn't have the right gasket, can I just use rv between the block and the plate? The new pump came with a gasket for the pump to the plate so that's not a problem. Thanks!
I don't see why not, use one that is oil resistant, I think Black is, and ensure the block and plate are clean and dry. If it were me, I'd just buy a piece of gasket material and make one, couldn't cost more than $1 or so.
The permatex ULTRA is superior for oil permeation resistance.
I would make a gasket as 68 nova said, it is pretty easy. Or go buy any machine shop, they probably have a plate to block gasket laying around that they would sell.
I use ultra on many builds, and never have any issues. Prep is allways important. Silicone applied to Clean and oil free surfaces seal and hold a long time when cured properly.