[midnight340]

68racer thanks for that input, I assume that's on a C10? or?

And Rob, I want to say I really appreciate the computations and the experience behind the knowledge.

On the installation on my F-1... in order to run low and to get good arm/frame clearance I had to pull the arms in a bit, putting the u-bolt partially below my c-notches which limits the travel I'd planned. I may modify the c-notch areas some... will have about 3-1/2" inches of travel (axle to frame) from ride height, but if I could run with only 2-1/2" spring compression I'd be fine.

So it sounds like I'd be fine with a 2" bodied (compr 3/ rebound 5) 7" shock (coil-over) with 2-1/2" 200-225# spring? Do I have this right?

And once I build the coil-over mounts (rectangular tubing across full width of frame) then I plan to x-brace from there forward to stock mid-crossmember. Should give me a good rigid rear section.