I'm in the process of building a 1950 Chevy 3100 also. I'm going with the original frame...had it sandblasted and covered with Chassis Saver paint. This past week I hung a 1981 Camaro 10 bolt rearend on it with 3" lowering blocks. I'm pleased with how the stance looks. Being 60+ years old, I had to replace the rear spring shackles and bushings...the leaf springs tended to sway in the gentle breeze! Next, (when mama's not looking at the Mastercard), I'm going to put a bolt-on Mustang II on it. I paid $200 for the 10 bolt...it is a nice one. I think the Mustang II will run me about $1500.