What you need is a bellhousing #3815891. This has the smaller bearing retainer plate hole. It also has the angled mounting for the crossmember to support the rear of the engine and your SM420. PM me if you need help with getting one of these bellhosuings.

There is a tech tip about bellhosuings. http://www.stovebolt.com/techtips/engines/bellhousings.html

Last edited by Cablesmill; 07/06/2016 5:14 AM.

1959 3100 Apache Fleetside