One other thing, I was planning on using a mid-80's BMW 535i rear suspension. It's a square tube with a pair of trailing arms on the ends. All very beefy, and it's 58" wide hub to hub, and fits chevy 4.75 bolt pattern wheels. Best of all, if you trim the diff mount off, it gives you enough room to slide a 500 and transaxle in between the wheels. The crank pulley is right up to the crossmember, but it works out fine.