Heater Blower Motor, How to remove it for replacement Options

[sburns1967]

I have a 1973 914/4 2.0 which is is partially disassembled.

It came with two hot air blowers:

Single Port - Working Motor
Dual Port - Dead Motor

In 1973 there was apparently a switch between the dual outlet blower to a single outlet with a Y pipe.

I was thinking I would like to use the dual outlet one so I thought I would swap in the working motor.

Two questions:

1) Does the dual outlet unit provide better heat flow through the heat exchangers than the single outlet with a Y connector? Any pointers to pictures of each type mounted/hoses?

2) How to remove the motor:

Removed the 6 screws on the motor flange
Removed the nut/washer from the cage fan

After doing so I can get zero movement from the motor from the housing. Even prying between the flange and the housing nothing moves.

Does anyone know if there is some kind of adhesive between the motor flange and the housing? If so do I apply a little heat maybe?

Thanks in advance
Scott