Anybody ever make thier own exhaust risers for sbc?
 

so, back in the early 90's, I helped make a set of 4" risers/elbows for some 454's. Worked pretty well and sounded great, but it has been a long time.

Has anyone made thier own elbows/risers here? Any threads, didn't find anything searching but never know what key words combination will work.

I need 3" exhaust for the hose and tips I have. the current outlet on the merc 3" elbows is about 2 3/8" so 2.5" pipe for the inner should work well with 3" for the outside.

Just wondering if anyone here has done this before or is this just something considered as a crazy idea?

Oh, will be going in a 272LS Formula with twin SBC about 295-300 HP each.

Thank you, Brian