I finally broke down and removed the blower to find out why I had no air coming through the defrost and heat vents. Four dead mice and a pillowcase full of mousenest later, I have heat and defrost!!! While the gods were smiling upon me, I installed the OE radio and speaker I found in an abandoned house. What a PITA! Gotta pull the ashtray bracket and the heater controls to get the radio in. Oh yeah, I forgot about the defrost ducts being in the way also.. Pics if anyone wants to see what an OE 70 Blazer speaker looks like.