My buddy has a 70 Challenger with a 440 six pack and I have a 70 Challenger with a 440 4 bbl. We both had our motors rebuilt and dynoed by the same shop nearly the same time. We have both put on about 1,000 miles on each of our cars and from day one his motor's temp is much hotter than mine. I can hardly hold my hand on the wrench long enough to loosen the bolt to adjust his timing.
I have the heat crossovers blocked off at the valley pan because I have an electronic choke, his are not blocked off because of the choke on the six pack. We both do not have a heat riser.
He has a new 3 core radiator and I have a new 4 core radiator. When I point the temp gun at my radiator versus his radiator they both are very close to the same temp, but his motor is much hotter. We both have 180 or 185 degree thermostat (can't remember which one for sure).
