?cooling system question?

[phuz]

1987 nissan 200sx SEV6

this summer the car started getting into the warmer region of the temp gauge, especially when using the A/C. this even happens while im cruising down the highway at 70mph. it doesn't overheat but it gets close to the hot region. i figured maybe the thermostat was going bad so i dropped a new one in (by the way, pain in the ass to get the rear bolt on the housing). same problem. the only thing i have changed since last summer is i pulled the four mechanical fan blades off, leaving only the electrical fan to cool. maybe sitting in traffic with the A/C on, i could understand the engine getting a little warmer, but not driving 70mph down the road. anyone have a similar problem?

matt