Well about 3 yrs ago i did a motor swap in my truck and did the plenum plate and felpro gasket with new bolts ! About to swap the 5.2 for a 5.9 again but should i put a new gasket under the plate or use it like it is ?

 

If it's still clean inside, you could likely get away with just leaving it. However, if you have the gasket, and its going to be off anyway....... Why not?