Back In June of 22 there was a discussion about getting more air volume thru the vents of the C-3s with A/c to cool the interior of the car. There was a guy on the forums that used a C-4 fan and motor. The fan and motor was the diameter as c-3 but the fan is an inch longer (deeper), so there was
a 1in plastic spacer crafted added to gain more fan area, the discussion on would that be enough to make any difference. I bought a C-4 fan and motor and carved the plastic stock for the spacer, and yes it does make a difference. Using an Anemometer on the old fan and motor it was gauged at 6.0 and with the C-4 fan and motor it went up to 8.o ms on the meter. So if you want slightly more air thru your air vents that would help a bit. I did replace the relay for the high speed (a/c cut off relay) fan due to the fact it was the original and after 5 minutes the riveted terminals started heating because of bad contact and extra draw from the motor and larger fan, the standard relay I used had no rivets on the terminals (maybe better?). I did also place matting with foil on the HVAC housing next to the engine to reflect some heat, it might help some I hope, every little bit helps.