The 1978 boats (the year mine was) had the pillow block on the tranny side of the bulkhead, so YES you can re-install yours there. It was moved to the backside of the bulkhead for maintenance...you won't be able to access it if you have a generator. You "may" have to drill new mounting holes as the shaft angle may not allow you to line up the oem mounting holes. If you do drill new holes you'll probably want to rotate the bearing mount 10 - 45 degrees so you can get good material around the holes.
The prop shaft will fit thru the hole in the rudder if you remove the prop first. You'll have to disconnect the rudder arm on top and manually move the rudder to 90 degrees, then the shaft will slide thru. (Some people install the rudder zinc over the hole so you may have to remove the zinc if this is the case on your boat)
The really hard part of this job may be getting the shaft to slide thru the old bearing. Clearance from bearing to shaft is very close, you will want to use sandpaper or similar to clean the shaft very good of corrosion and nicks before to even start. OR you may want to grind the bearing off that might be easier. (Mainshippers have done it both ways)
I have done this job 2 times myself on my ex 1978 so any more questions ask away.
New Port Richey,Fl