Don The S 10 i used was a long box so i had to shorten it which is pretty simple because there is a factory seam by the trans crossmember so you just grind out the factory weld ,shorten frame to right length,square it and reweld.This swap is best if your frame is weak and the floor is in poor condition because you have to raise the rear floor pan and trunk floor due to the sweep of the S10 frame so if your frame and floor are solid it would be easier to just use the front clip and join the two frames around the firewall.The S10 is a little narrower than the camaro and nova so they fit a little better for width in the 30's cars.This is only my own opinion though and i'm far from a expert Murray