slant bellhousings

Thanks! I have a friend with the od bell. Is the adapter ring the only mod required to use this bell housing?
According to Brewer's:
Bellhousing cast #4202506 is for '81-'86 truck only.
#3743643 will fit A & F bodies, and '76-'80 trucks.
Find out which bell he has.
Both are listed to work with your 122 tooth flywheel.