what are the best short tubes for hot rod cams

If all you are concerned about is the smell you might want to try some Magnaflow spun metallic cats mounted as close to the headers as you can get them. When I had my 85 it used to stink up my garage terribly and the scent would come in the house if I closed the garage door with it in there still warm. I put a pair of the Magnaflow cats right before the crossover on the off-road H pipe (not optimal placement but the only place they would fit) and it cut the smell by probably 75 percent and didn't change the performance or sound at all.