911 Overheat need options quick

Yes I searched thoroughly and read. I have a 2000 DD 4.0 w/ 0331 head. Problem 1. Its hot. Just replace radiator, hoses, thermostat. After replacement ran 195-210. Perfect. 3 mos later it starts running 210 steady and up to 215. It spike today to 260. It blew off into the overflow but not out. Left it cool filled it up and started it to push out the air, it started spitting out the radiator neck. Then it stopped. I assumed it was boiling water, because it was hot, thermostat open/ thermostat close. Heres the bad part. I can set up a set of gears but no little about engine internals. I was already ordering a new water pump, but now I am thinking the head gasket or worse crack. I have not been losing fluid till now. I runs in my train of thought that since the heat was going up the pump may not be pushing enough. Oh, when it starts getting hot if I drop to 3 and drive it almost immediately drops the temp. So I need help where to start- pump or new head??? FYI i am low on funds and appear to be getting laid off in a while so cheap is good.

Is you electric fan not kicking in at around 220-225 degrees? There are several thread here about checking that and making sure it works.

Also, I would also check the mechanical fan...maybe you need a thermoclutch.

There have been several recent thread about that as well.

Dumb question...when you replaced everything, did you replace the radiator cap as well? A bad cap won't allow pressure to build, so your coolant temps will rise and boil over.

Hmmm, that's a bit confusing, you might get more answers if you rephrase a little clearer. So you had overheating probs 3 months ago and bought a new radiator? And that seemed to fix it until today when it spiked to 260? And now, you're actively losing fluid when you drive it even when its not overheating?

Is that right? If so, give specifics - what kind of new radiator, how much fluid are you losing, etc.

Also, don't drive with 260 temp or anything close, not even a short distance. If it's much above 220-230ish, you're risking engine damage and serious $$$bucks to fix it, whereas most cooling problems can be solved for well under $200, sometimes even free, if you diagnose properly.

How many miles?
Have you been loosing any coolant?
When it spiked to 260 where you driving or idling?

overheating while idle is usually fan related. overheating while moving points more towards waterpump (since you just changed your radiator). Thermostat could be stuck. Thats an easy, cheap fix. radiator cap is also a good suggestion.

My 0331 head cracked almost 1 year ago. Mine started running warm (215-220). I thought a good coolant flush might do the trick. It did for a while. The flush got me back down to 195-210. That only lasted a couple of months. After the flush i kept a close eye on the overflow bottle. I went through about 1 gallon of coolant in 5 months. I couldnt find a leak anywhere. I finally began looking into the cracked head.

Take off the oil cap and shine a flashlight in there. You should be able to see some coolant residue in there, and possibly see the crack itself. You could also start it, and once it gets up to temperature, you should see coolant 'bubbling' up from the crack.

Here are some links to my head change out results:
https://driven2services.com/staging/naxja/xf/index.php?threads/935856/
https://driven2services.com/staging/naxja/xf/index.php?threads/937214/