Putting a C-4 in my 1986 Mustang GT. Need to know what flex plate to get for it? I was told the C-4 came from a mid-late 70's Mustang and is the smaller 157 tooth bellhousing. I'm trying to look the flexplate up on partsamerica.com but the 5.0's all came with 164 tooth ones. SO maybe the transmission came from something else ? I see one from a 1970 Mustang 5.0 with a 157tooth flywheel. That one would work I assume? Some info would be greatly appreciated!