340 stock manifold to header adapter question
TTi makes headpipes for the 340 manifolds, but they don't have collector flanges on them. You could add the flanges to the headpipes or leave them off the exhaust system and just hook them up with slipjoints.
They're kinda pricey for what they are, though. I would think a local exhaust shop should be able to fix you up a little cheaper.
Exhaust_Parts