I've got an aluminum bellhousing from a SM465. I'm trying to find out if it can be used for a sM420.

I know that the SM465 and SM420 have the same bellhousing bolt pattern.

But I believe the SM420 has a smaller bearing retainer than the SM465.

Will a SM465 bearing retainer bolt to a SM420 thus allowing the use of the SM465 bellhousing?

Thanks in advance for ANY help,
John

yuo can make an adapter ring for the 420 to center it in the 465 bell.

Any idea of the inner and outer diameter of such a ring?

from Novaks site (http://www.novak-adapt.com/knowledge/sm465.htm)

Identification
The SM465 has a case length of 12". It is also identifiable by its large, 5-1/8" diameter input bearing retainer

from Novaks site (http://www.novak-adapt.com/knowledge/sm420.htm)

The SM420 enjoys wide compatibility with most GM engines. It's 4-11/16" front bearing retainer indexes to many GM standard shift bellhousings, including Buicks, GM cars and pre-‘67 GM trucks. The latter are common donors of the SM420

It is important that you measure the locating bore on the bellhousing to confirm the 4-11/16" diameter before performing the swap. Note that it is possible to machine an indexing ring so that transmission may fit the larger 5-1/8" bore. We or a good machine shop in your area can make such a locating ring. Note that both two and four-wheel-drive versions of the Muncie 420 are compatible with our kits.