OE Spec Stamped Steel Flex Plate Stock replacement, solid style
When hooking up a Caddy to a Chevy or GMC converter, you have to keep in mind that the bolt pattern on the converter must match the hole pattern on the flex plate. TH-400, 4L80E, and Allison converters generally have the “large” diameter pattern (11.5″), but light duty trannies (‘Glides, TH-350, 700R4, and TH200) have a smaller pattern (10.75″). You cannot safely drill out the stock flex plate, because the smaller circle falls on the stress ridge on the Cad flex plate. Three holes in there, and your chances of blowing the middle out of the flex plate are pretty good. All of our aftermarket and OE replacement flex plates and flywheels have a Cadillac 166 tooth ring gear for use with a stock Cadillac style starter. All are zero balanced like stock and compatible with any 472/ 500/ 425/ 368 Cadillac engine.