Thanks Guys, I will go with the 3 x 1.5 and weld the ends in, was hoping someone had the measurements all done for a dart body....hmmmm, maybe I will have to draw something up after i"m done.....anyways, what gauge steel did you guys use, I was thinking 1/4 would be enough. The T in the front is striaght forward, how much of the rear rail should I go over ...6" ...or more? Thanks again