with your choices stated, I can build it for $580 plus shipping ($520.92 in parts). PM me if you are interested.
IBM laptop and HP laptop (junk when started, everything is branded now).
78 K20. 400SBC Dual Quads, Muncie 4 speed, NP 205, Dana 60's at both ends with 4.11 gears.
86 F250. 540 horse crate 460 and ZF6. Dana 70 rear with 3.73 gears. dual stacks to vent the dual quads lol.