Ok, now I understand that replacement may be somewhat complicated.  Here
is the situation:

I got the motor out and ready to install.  Time constraints require I
get the thing "mobile" within next few weeks (I always factor 3 times
what I think repair time will take, so with only the weekends free, I'm
sorta on a crunch.  I would like to replace the tranny oil seal, there
is some "sludge" buildup inside the bellhousing that I gather may be
from a leak.

However, I really don't want to pull the tranny now (that would more
than double the time it will take me to get this rig on the road.

Questions:

1.      Is it possible to replace this seal with the tranny in place.
If so, how?  (I have a connection to get the seal

2.      If I do not pull the tranny now, how much work is it to pull the
tranny later, leaving the engine in place (or is this even possible?).

Thanks for the advice on this one

Philip