Thanks are due to the brickboard once again for helping me save some $!!
I'd like to share my experience in changing a dying heater blower -- was getting so noisy (like an old coffee grinder!) almost seizing at low speed (we had to run it on #2, then #3 speed all the time).

The FAQ were very useful. I also did some research on aplusparts.com where I found out that 1989 was a threshhold year for blower models. Also checked what was offered on ebay.
Taking out the blower was not that easy. The motor housing -- which one accesses after removing 2 plastic panels, the ECU and its bracket -- was secured by 5 hex screws, 7 mm size and the 2 in the back were a pain to take out and put back: you need a very small key, more than a pinch of patience, and should be able to work with your left hand. Watch out, many key sets start with 8 mm hex heads! (which was the size of the screws securing the ECU).

I washed the squirrel cage as instructed in the FAQ, very reuseable. As a sealant when putting the motor back in place I used glazier putty which I had handy. It is adviseable to do some yoga, tai chi or stretching exercises before (and after) this procedure... especially if you are over 40.
I spent well over an hour taking the blower out; even more to install the new one in. I had disconnected the battery but finally left the ECU plugged in and pushed it aside.

My blower was the one pin-type so I got a Siemens PM105 from Autozone (assembled in Mexico) for less than $16 incl. tax!! it wouldn't have been worth cleaning the old motor, which was rusty and almost dead anyway (rotor was worn out in places from friction on the magnets, not revolving properly obviously). The only noticeable difference is that the new motor housing is riveted, the old one had brackets one could bend to open its housing.

Interestingly the 17 yrs old motor on my Belgium-made 745T was a Delco made in Dayton, OH. Here are the refs if one comes across an new old stock:
5048837 81X0558
But I think that $16 for a new, warrantied one, would be hard to beat (I guess one guy on ebay is doing just that, buying it from Autozone and selling it $30-60 on ebay). This is where I say: my $20 "brickboard due" of earlier this year has already paid off!

Good luck to all of you replacing heater blowers, by the way. I read that it is even harder on 240s...