Its getting hot, damn hot. Radiator and fuel problem

[sqrlnts]

Long post with as much info i can think of. Thanks in advance for your help!

Couple problems with the truck as the temperatures rise to 110 plus here in Phoenix. Daily driving home from work in the heat of the day my truck is vapor locking. Have also noticed the radiator tends to allow fluid to escape the cap rather than enter the overflow once I park.

The truck runs and drives perfectly in the morning with AC going and even ok up to about 105 degrees outside, no vapor lock, 190 max water temp, AC is blowing the entire way as its already 90 degrees at 8am.

My commute is 4 lane surface streets approx 10 miles in stop and go traffic, 45 MPH speed limit. The more red lights I catch the more pronounced the problems are. The water temp hovers very near 215-220 at the warmest just before I get home. I am running the AC the entire way. Again, this seems to be a recent issue with the severe heat driving home after work. It runs fine in the morning and has also done fine all winter long.

What I know and have done so far.
The stock '73, 350 is timed at 32 degrees.
Ceramic coated headers, 2.5" exhaust dumped in front of rear axle.
recently added a 1/2" wooden spacer to the Quadrajet carb.
Aluminum Edelbrock RPM intake
I have ensured the rubber fuel line is not against anything hot.
Recently replaced the fuel filter
newer upper and lower radiator hoses
2 year old Champion 3 core AL radiator
1 year old 16lbs radiator cap
1 year old 16" Maradyne electric fan with shroud.
Flex-A-Lite fan speed controller. Fan runs at 100% when AC is on.
2 year old sending unit and sock in tank.
2 year old Aluminum fuel line running along the inside frame rail, no return line
I recently insulated the carb gas line from the mech pump to the carb.
I also added 3' of insulation on fuel line just prior to the fuel pump.
Newer 180 degree thermostat.
2 year old radiator overflow tube into bottle, need to check rad neck orfice for blockage.


What i don't know
Water pump condition. I know its pumping fluid at idle in the driveway.
Fuel pressure when hot. No FP gauge installed.
Radiator cap was replaced a year ago but not tested.
Have not read spark plugs.

Again, thanks to any and all who can help. Feel free to ask questions. Here is a picture cause I know they help to visualize things.