I've got an 87 g.m.c custom deluxe w stock 305 and everything else is stock. it is a 1/2 ton (not exactly what I wanted to build up) I was hoping for a 3/4 ton and go big block but I bouhgt the truck as an every day driver back and forth from the driiling rigs i was working on, and I got a good deal. the truck is in good shape. I was going to sell it and buy an older 3/4 ton so I could go big block with a little heavier suspension because I am extremely hard on equipment when I go out. But I overheated it when i was out last time and warped the head so i will never get out what I would have to put in so i guess I am keeping it. so what I am looking for is tips and problems I should watch for while I am building up. I want to go big block and i would like to put under 1 ton or 3/4 ton at least dif's. i would like to go up but not crazy i would like to run 35, 12.50s with out any problems. how high do u recommend. what is the best way to run a duel battery duel altenator system. any ideas or expeiriences. how many probs do u see with the big block and the dif swap. also to go from throttle body back to mechanical how much headache is that. I would really appreciate any input from other people who like and know trucks thanks.