3/4 ton back half build

[chopped65]

This is my first build thread. The truck is a 1965 C-20 that I am retaining all the 8 lug. The front end has been converted to disk already with Brothers drop spindle disk brake kit. I already have my wheels and tires. I bought the tires first to build the truck around which are the Mickey Thomson S/R's 31x18.5x20. The wheels are Helo Maxx 8 20x10 and were sent to a custom wheel guy in Azusa, CA to be widened to 20x15 and had the tires mounted on the wheels. My axle in the truck now is the Eaton HO52 and I bought a Dana 60 off of craigslist with 4.10 gears and a locker in it. Dans Driveline in Las Vegas, NV is going to narrow the axle housing, change out some bearings inside and measure everything for Moser to build the axles. 7 years ago I bought an aluminum under bed fuel cell from Brothers so I am eliminating all the rear frame and building everything new. I will be building a box around the fuel cell and that will be the rear section of the frame.

What I've done so far as I am starting this after I started. I built a cart on wheels for the bed which is in the pictures. Before removing the bed I removed all the electrical, fuel lines and pump, drive shaft, exhaust and fuel cell. Then removed the 8' bed with one other person. WHAT A PAIN IN THE A** THAT WAS! for only 2 people. I removed the panhard bar mount and the bed mounts from the frame. I boxed the frame using 6" flat stock 1/8" steel. I boxed from the trailing arm crossmember (back of cab) to about 26" in front of axle centerline. Did this with two pieces as the angle of the frame went up in the center of that point. Ground all welds smooth to make nice and pretty. Next which I should have done first but it didn't effect anything was that I leveled the complete truck in the garage which was difficult with the crooked garage floor. See pictures for my shimming on the jackstands. The rear right jack stand had to be shimmed. Created a new mid crossmember with 2x4 .120 wall tubing 30" in front of axle centerline. The 30" is measured to the rear of the crossmember closest to the axle. The new crossmember is "pressed" in to the frame, it is a precise fit. The tubing has been ground at an angle to make the weld solid. I still need to weld this in, almost out of gas so probably don't have enough to finish welding this in. Next steps are welding the crossmember in, building braces for the crossmember and welding those in. I am ordering my center frame piece from Nate at Porterbuilt which will go from my mid crossmember to the front of the frame box that is around my fuel cell. See drawing. The center frame piece will have a large step notch as this will eventually lay frame and with the 31" tall tires it puts the axle sitting pretty high to clear. While Nate is building that I will be building the frame surround for the fuel cell. I was just going to make the frame go straight back from the mid crossmember but since I spent so much 7 years ago on the fuel cell, I will kick the frame back out to fit around the tank.

Where I am at right now is: what kind of brace do I build for the mid crossmember. Do I make it a K Member and make larger 12" braces at a 45 degree angle (guestimate measure and angle), or do I make gussets?