That extra weight over the rear axle helps with traction and autocross events!
I couldn't get mine to fit right either, so I ran them front to back using the cross members below:
Check out my old thread here, especially post #3.
http://67-72chevytrucks.com/vboard/s...d.php?t=197895
It's been under the truck almost 11 years now. It actually worked out because I bought a hitch for the truck and it wouldn't have fit with the straps the other way.