SportF nailed it. 100% correct. You don't want to use the one hole filter on a valve body made for the two hole/rear pump style application.

Seals remain dimensionally the same from 1962 - 2008 for all 727/46/47/48 transmissions.
The later style has helical lips in the ID that helps "pump" fluid in to the trans to prevent leakage.

Last edited by Transman; 03/20/18 07:29 PM.