poking around parts supplier's www sites, I found that the deluxe (fresh air intake) heater's core is 9-1/2" long vs the standard (recirculating) heater's 6-1/8" length. These cores are 2-1/2" thick, thicker than 67+ heater cores, so I am thinking that I might possibly modify my heater case next winter when I have time, do some sheetmetal fab and mig welding, to make the larger heater core fit into it, and then build a box off the single outlet and make duct connections, and duct my heater to some vents that I would have to add under the dash in 4 or 5 locations. That would save some money, keep parts still as readily availble as they were (have to possibly modify heater core hose connections with some tubing, refrigeration copper fittings, and a torch and solder...).
I was looking at all sorts of suburban and van heater cores, and it looks like the deluxe fresh air unit has the best donor core for this project. my 62 uses the same cores that a 61-63 would use. looked up a 66, it's 2" smaller than the 61-3 deluxe core.
I think using one of these larger cores, be it the deluxe or the 66, increasing the area, and using a 190 degree stat, those might be enough to help heat a suburban/panel truck a little better.
Still thinking of the vintage air evap kit that would basically let me bolt their heater right into my truck without using their A/C, but if their fan isn't any bigger, there might not be a point other than to save me doing lots of fab work on my stock heater case.
also checked, the standard and deluxe heaters use the same blower motor. no way for me to verify the size of the blower wheels between the two units, but they might likely be the same if the motors are.
