Before I put back the rear transmission case housing on the transmission rear case, I am wondering if using permanex gasket spray (copper) on both sides of the gasket and two coats in between drying times of around 20 minutes is ok? Anyone out there have done this or is it necessary to use permanex gasket spray on the housing gasket? Feedback, comments, advice, etc., is greatly appreciated.

Install it dry, if you need to stick it to the surface, 2 or 3 dots indian head shellac or rolls royce hylomar works great.

Dont use sealants that are not compatible with atf and cause issues when used over gaskets.

I believe copper rtv is heavy (thick) body sealant, such can cause clearance issues or if torqued with a gasket can tear itself and make leak paths