Having a 3600 has it's advantages. It's 3/4 ton, longer bed, heavier duty suspension. Plus, it's not like nearly everybody else's 3100 short bed.
I'm building a 1950 3600 rod project. I have a 14 bolt rear axle with 3.21 gears and even though it's a snug fit, it works for me.
Built a 350 v-8 and mated it with a 350 tranny.
Click below my signature for some pics of my build. I'm not finished yet, but I'm making good progress.