know where I cawhere I can get an an aftermarket exhaust manifold 83 inc 83 inch A inch d down pipe and 4 inch exhaust and would like to do the manifold is well any thoughts on that or knowledge about if it's worth it I'm also wondering I do blow black smoke but even just running I spit out quite a bit of grey but I still seem to have full power?

 

Get the 2 1/2" crossover pipe from most anywhere.Ebay,Hearthrob vendor?
The 4" Diamond Eye exhaust is available from Alligator performance,and manifolds are easiest to find on ebay or the local wrecking yard.