My truck is a 1986 GMC Sierra Classic K1500 4x4. I've had it for 5 years, it was my first vehicle and I plan on keeping it forever. When I bought it, it was lifted 4" (skyjacker softride i believe) with new 35x12.5x15 BFG AT's. The truck was clean with no visible rust. About 2 years ago, my stock 305 motor overheated and I had a 350 installed. Now, my truck is in need of some work. I mainly just want a solid, dependable truck to drive, do some offroading, and pull a boat with (18'ski boat). So here's what I need opinions, suggestions, and help with: 1. Transmission. My 700R4 is slipping and needs replaced or rebuilt. What is my best option? Local rebuild? I've searched and found good reviews of the bowtie overdrives, could a first timer install one themselves? 2. Gears. Mine are stock, not sure what ratio (any easy way to find out??) I'm thinking 4.56 would be best? What would be a good locker/limited slip to put in the rear for my intended use? 3. New tires. I've liked my BFG AT's, but would like something a little more agressive like a BFG MT. What else is a good tire? 4. Rust. My truck has developed rust in the cab corners, rocker panels, above the rear fenders, and around the tailights. Where's the best place to find replacement panels, etc. Thanks for your help, sorry this was so long.