1993 Toyota Pickup Engine keeps trying to overheat

I just did a major head gasket replacement on my 93' Toyota pickup. Before I replaced the head gasket, I installed a new radiator and thermostat. I have also recently replaced the alternator. My problem is that now the truck is still trying to run hot after I start driving. The temp gauge will sit at about 1/4 then jump up to the 1/2 or just past and stay for a minute. So far it will then drop back down to 1/4 temp. The truck is also accelerating/idling rough. What else could be causing the jump in temperature?