I have a 72 skylark with a 90,000 mile 455 and turbo 350 and 2:56 posi rear, we just swapped stock 455 with built turbo 400 and 2:56 1 leg rear into buddies 71 GS, wondering if we will have a friendly run before the 3:42 posi goes back in his. Still think we should do this whynotbuick!