Trying to put together a budget performance exhaust system with individual runners in manifold & SS risers. Does anyone have experience with GLM manifolds & Imco SS risers on a sbc in a Classic 18? I saw Rootsy sold a similiar setup in 2010 and wonder who has performance experience with this setup? I run in salt water and fresh water cool the engine but raw water cool exhaust manifolds & risers. Any systems for sale? Thoughts? Thanks, Bob