454cid
Sooper Pooper
You are correct - w/6.5 TD. It was only for comparison with the general height profile to show the difference between the trucks, unless you're saying it's night and day to compare?
I'm saying it's not showing anything relevant to the conversation because the trucks aren't the same or even similar, as far as the frame and suspension. One truck is a K3500, the other one is a 3500HD. The bodies are mostly the same, but the frames and suspensions are completely different and share no parts. The 3500HD is closer to a commercial P30 chassis. It uses an I-beam front axle, a Dana 80 rear axle, and the frame is huge.
Given the picture the OP has provided it really looks like the T-bars are just cranked, to me. The control arm angles and CV shaft, look like they're further from horizontal than GM would have put them.
Edit: The heavy box on the back may be contributing to the squat, too.