Steve, As you know, my Alpine V6 has the A/C unit also.
It is from Vintage Air and has both the A/C & the heater option.
With the heater option I removed the stock heater core and the factory fan.
The reason why is simple,
reports of the core bulging and bursting under pressure above 7 lbs caused me to take that bit of caution in advance.
I run a Stant radiator cap Number 231 with 16 lbs.
My stock radiator was re-cored to copper with three tubes.
A factory/stock Alpine radiator has
nine (9) fins per inch vs My new re-cored one has seventeen (17) fins per inch for better heat dissipation (IMHO).
I too run a radiator shroud I fabricated specifically for my V6 modification hoping to get away from any potential heating problems. So far so good.
My A/C condenser is mounted right in front of the radiator with very little spacing.
All or I should say most holes are plugged to help direct air flow to the radiator.
The radiator modification I recommend using is with the "top" left hose connection angled about 7 degrees toward the water neck on the intake manifold and the bottom right having the 90 degree elbow downunder the tank pointing directly across toward the left side to the modified thermostat housing. By utilizing the Gates hose 22080 for connecting the 90 degree elbow to the modified thermostat, the hose actually serves as a blockage between the crossmember and the bottom of the radiator.
I have been driving in some very hot conditions here in Sunny SC and during noon traffic at times with out heating problems so far ( And I repeat so far).
During the UNITED XXXVI there was no heating problems encountered during my driving times. Only problem was I had to push it off the first morning ( w/Joel Griffin & my Son's help) due to a bad battery.
Steve, maybe it is that nice EPS you have installed in that beautiful Red Alpine
DanR