Ben Taylor

I have an 81 that has a pretty weak blower motor, I'm going to change my Heater Core in the next couple of weeks, where can I get a stronger blower motor?

Smokehouse69

Ben,
You can get a new motor, but first check and see if it is actually running a full speed. I think you'll also find out that the a great deal of the lack of air volume is caused by 21 years worth of leaves and other crud inside your evaporator and heater core case. There are a number of other things that cut down on air flow. C-3's are notorious for poorly fitting duct work, while you have the dash out for the core change, make sure you seal all the ducts. Adhesive foam weather stripping from a home improvement store works pretty good. Also tape around all the connections between the ducts with aluminum duct tape. (Not the gray duct tape, it will peel off, but real aluminum duct tape, also available from home improvement stores.)
If you find your blower is bad, then the best place to get a replacement is from the Chevy dealer.

QuickVet

aww man. i thought you were talking about a supercharger ;)

Dalannex

Smokehouse69 said it all. I completely rebuilt my heater box and duct work and now the blower blows more than you can hardly stand on high. Like he said, there is a lot of material that needs to be cleaned out of the heater box, core, and evaporator.

lou

Just redo all your seals while your in there. You will be surprised how much more air you will gett from a fresh blower motor. My air flow almost double when I replaced it
lou