EFI LIVE is the best, how be it I cant afford one yet - $900 ouch!!! or find someone close that has it already and throw them $200, dyno shops can do it and fine tune the truck
or do a 5.3 they are cheap now days, and deliver good power with decient millage, get an adaptor and bolt it in there, wiring, ECU, fuel system, and exhaust to start with. do a camaro TPI - simple wiring mods, fuel pump swap, reprogram the chip, exhaust would bolt right up to the stock 1994 350...
LT1 with TPI, here the article does not have the TPI on it but the motor does have it now http://www.gmtruckcentral.com/articles/lt1swap.html my truck 15 -16 max mpg
1999 K1500 with a 1992 TPI 350 upgrade...