I need to pull my factory C6 from my 73 vert because it is leaking. The car has a 351C-4V (stock) and 3.89 gears. The transmission has 70,000 miles on it and still shifts well. I've heard that this transmission is a real power hog and that I might be better off with a C4 or AOD. Since my motor is basically stock I'm sure the smaller transmission could take the abuse. The advantage of the AOD would be the overdrive (especially with the 3.89 gears). How complicated is this swap? What vendor did you use for the new tranny? Would I have to replace the flexplate and starter? How about the crossmember? What's involved in hooking up the shifter and kickdown?