ATI flex plates fit aftermarket converters only. Ford Flex plate kits include flex plate, CNC-machined crank piloted spacer and crank bolts. Ford flex plates with 164 teeth have an 11-7/16" bolt circle, and flex plates with 157 teeth have a 10-1/2" bolt circle for Ford converters. Both have factory installed 10-3/4" & 11-1/2" bolt circles for GM converters but only the 10-3/4" bolt circle is usable for the 157 tooth flex plates due to ring gear interference. 184 tooth FE flex plate is 11-7/16" Ford bolt circle only. ATI Ford Flex plates are flat. They will accommodate ONLY converters where the drive pad is ABOVE the converter body.