During my Summit trip, I snagged a SpeedTech frame stiffening kit PN 30710. They had mislabeled it in the clearance section as fitting 64-72 A-body GM, but I learned later that they are two different kits for 64-67 and 68-72. Since it was in the clearance section, it's non-returnable. Summit (being the awesome entity they are) agreed to refund my money if I sent it back, but the cost of shipping kinda sucks.
While I have the option to send it back (and might) I thought I'd offer it to you folks in case you wanted it. I paid $533 with tax. They're $800 new. If you have a 68-72 A-body and want this kit, I'll sell it for $500 you pay to ship. It is complete and brand new, still strapped in the box. It is complete, but missing the 4 or 6 bolts it's supposed to have.
Stock photo.