Revs oscillating after overheating incident

[yotatake2]

So i was driving up the Rockies with about 1000 pounds of people/tools in the back and my radiator blew up. I was revving at about 5k rpms to keep up with my friend when the radiator just gave up the ghost. Swapped it out easily because i have a separate transmission cooler so there was one less system to worry about.
Anyway. It was still overheating the rest of the way from Denver to Beaver, UT and occasionally on the way back to LA. It's no longer overheating now. My heater still doesn't blow hot but what's more concerning to me is that whenever i accelerate, maybe 4 times out of 10 when i get to around 2000 rpm, the engine will start to rev up and down between about 2000 and 2300 rpm. It'll do this until i either give it more gas or let off the gas and try revving up again.
Anyone know what this could be?
And as far as the heater, i bled the system and it's still blowing cold. Clogged heater core maybe?

 

[shootmymime]

I bet it's clogged with air.
Your rev problem, head gasket with all your overheating?

You can back flush it. Take both hoses off. Stick the inlet on the outlet and start it up. But keep your radiator topped off or stick a garden hose in. Also I heard dawn liquid dish soap works good. Squirt that inside b4 you do your back flush.

Ok when you do try to burp the system park at a steep incline with the back down and front in the air. Then run the car.

 

[yotatake2]

I'm pretty sure the head gasket's fine. There's no white smoke out the exhaust and it's not overheating anymore. I had the whole coolant system flushed when i got back so I don't think there's any more air in it either.

 

[yotatake2]

any other ideas? dirty MAF maybe? I'm guessing there's some sort of miscommunication with the throttle body. But I always thought our trucks had a purely mechanically controlled throttle (except for when in CC), so it confuses me why the throttle would suddenly have a mind of it's own like that.