I am in the beginning process of building a 41 chevy coupe streetrod. I have the chassis engineering mustang two front end in, an LT1 smallblock with a 4 speed auto. the body is off the frame right now. I want to narrow the back half about 4-5 inches on each side. I want to run wider tires, but use the stock gas tank. My plan is to weld in a 2x4 box crossmember first(just in front of the stock leaf spring mounts), then cut the rear frame rails off, take a chunk out of the very back crossmember,re-use the same rear frame rails just closer together. Anybody done this or have a better idea? thanx, jack