Have a GM cast iron adapter ring for the V8 engine, Google says it fits all cars and trucks from '56 thru '61 with the PG transmission. PN# 3742366 and is cast with " D 8 58 " which I believe would indicate an April 8, 1958 casting. Also above the PN is " G M 3 " (?) Has been glass beaded, all threads have been chased with a tap and are in good condition. No cracks, does have a small issue on one "blind" bolt hole but will not effect mounting in any way. Asking $65 plus shipping.