well you could put a whipple supercharger and it will pull and pull.... a customer had one on a 1990 chevy in time i built him a engine for the wipple he order the smallest pulley for the blower and was at 10psi of boost it was fun .the bad news is whipple will not build you a kit for the 1990 truck . you may find one used on e bay ? before you buy one used call whipple see if they will rebuild the blower . what glenn said would be good start .i would look at a big bbc like 496 or bigger 512 .if yours is in good shape you could do the top end and cam . but if you go that far i would make it bigger in CID