Im looking to swap a 1994 LT1 and t56 6 speed into my 78 Silverado with a 350 and granny four speed. What is the easiest and cheapest way to make the tranny work with what I have and / or what modifications will I need to make? It's a C30 that came factory with a 454 and 4.11 gears with a lwb fleetside bed.I'd like to keep my clutch assembly I have, but willing to change over if necessary.