RE: la.40 hop ups
Yeah, you can improve the exhaust...even put a pipe on it, but you still have the small carb. with the (relatively ) tiny .220" venturi opening.
Maybe one of the Profile Brothers can tell ya about a "Mousse can muffler"...I seem to recall others having success with those.
You might try a different carb. but the neck's opening in the case is still small.