DragRacer404

iTrader: (8)

Is there any kit already made for the Chevelle with an LS1 for a procharger kit, or maybe even a twin turbo kit?

Dub Silverado

iTrader: (5)

You could buy a pro charger kit for a ls1 as long as you are using factory accessories. Twin turbo or most blowers are all going to take custom fab work.

pist0lpete

iTrader: (3)

My guess is turbo will require some custom turbo manifolds etc. but you might find some off the shelf ones that work. As for procharger I believe there are kits for the GTO, F-body. and Corvette out. You should try somebody like exotic performance(a sponsor on the right) and see what they think would fit best.