I would personnaly search ebay for a holly 2DFI system. Used you can find a complete setup for under $200. This is only fuel side, your engine would still retain the existing spark side. Adjustments are simple, idle screw, power screw, richness screw.

Or you could find a GM TBI unit from a 4.3, get the complete setup and install it. It will run fine without having to go Megasquirt which can be difficult for those that havent soldered a MS kit together or programmed EFI on their own.

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me