Outer Limits 4x4 Board

I am about to pick upa 60 series shell. My intention was to cut it into a trayback ute. Question is..... what I wanted to do to form the rear rounded edge (not using rear tail gates) was to get a 3inch bar bent to the contour of the cab, then welding the roof and sides to it. After doing that I wanted to get a sheet made to fit the rear panel, so as it would also be welded to this bar.... thus the bar giving the finished rounded effect.
Will this affect the flex of the cab and cause the weld to crack.... or any other foreseeable problems???? I would also be making a twin bar approx 50mm higher than the cab for the tray, incase of rollover.

Any advice would be great.

If the bar isn`t welded to the chassis and the body only it wouldn`t matter but thats a pretty weird way of doing it

I think it will be hard to avoid heat distortion when you are welding thin sheet to the 3" tube, and it will take lots of filler afterwards to get it looking smooth. The location and rigidity of the chassis body mounts will determine if you get cracking or not.

IMHO I think it would be better just to use a hammer and dolly to shape the curve by hand.

a bloke here in canberra cuts GQ's into utes exactly the way you have described. he uses 2.5" exhaust tube. comes out very strong and really neat.