71 Jeepster Commando, heater upgrades

I've replaced the core with a new one. installed a 195 degree thermostat. Cleaned all cables and doors. Everything is working as good as it can. Still, air coming from heater is luke warm, at best. I've heard of different motors being used, for more air flow, but don't know which one to get.
I know insulating the cabin and installing weatherstripping will help, but still, the output of this thing sucks. My 61 Willys wagon heater works way better than this thing.
Any tips will be greatly appreciated.

 

Heres some links on it.

http://www.americanjeepsterclub.org/tech/fixtip5.shtml

I remember reading a blazer full size motor can be made to fit also.
I think you have to put your fan on it.