98 Transport - Overheating

Please can someone point me in a new direction cuz I'm running outta thoughts (and funds! to fix it!!).

Bought a 98 Transport with a 3.4 earlier this year, and was told the guy had just done the intake & head gaskets (the 2 major bads on this motor)

Now fast forward 1 week ago it started overheating, I was able to loosen the bleeder screw to get myself home. Then the next time I tried to drive it it pegged out in less than 5minutes.

So in the last week I replaced:
Thermostat
Water Pump
Flushed radiator
Intake Gasket (with the new type that is supposed to not go!)
Spark Plugs (since its the best time to do them!)
Complete oil change w/ filter
Air filter (didn't have one on it before)
Radiator Cap

There was/is NO white smoke, so I didn't do the head gaskets.

Today after it was back together, I took it for a test drive and it was fine at first... temp stayed down for about 30mins. But as soon as I took it acrossed the street to buy more antifreeze it pegged out. So I let it cool down, then drove to the autostore about 3miles away and the temp was back up around 250... I bought the Radiator Cap... and it was pegged in less than a mile... had to stop twice in that 3miles home... finally I loosened the bleeder to get me the rest of the way home :mad:.

Now its running in my driveway for over a halfhour while I find the source of the airleak I'm hearing... and its sitting happily at 215-ish...

And idea why it keeps overheating? This is our only vehicle and my wife hates having to get rides to work.

Thanks for any ideas u got!

My first suggestion is to just shoot it and be done with it. My 94 with a 3.8 over heated this weekend to well over 260. It is on its 3rd engine. It has a new radiator (1 yr ago). Just had the rear manifold replaced one week ago and that itself was a job (hard to find, took a month to locate a used one) and two days ago the transmission oil cooler line broke. Try and find one of those. This AM found a radiator shop that will make one. The CASH for CLUNKERS was useless as the car is tagged @24 mpg. If it was possible I'd give up. We have been through pure helll with this beast. It is as about as trustworthy as a fox in a henhouse.:runaround: It make us crazy. But the air conditioner is A-1, that was replaced about 5 yrs ago.

Update:

I replaced the radiator... still nothing.

Soooooo by process of elimination, I changed the head gaskets and put it all back together for the toooo-many-ith time. So as of 2am this morning, it appears to be fixed. Going to drive it out and about today, and be sre.

Had 3 broken bolts so its a little louder than it was, but I'll tackle that this weekend, should be an easy fix (on this motor, yeah right!)

I was going to sell it, but after putting this much money into the major fixes, why bother

I was thinking head gasket due to all the other stuff that was done but never know from afar if the work was done right & may not have fixed the problem.

Anywayyy.. I hope the head gaskets work out & that the heads were checked out prior to putting them back on? Ideally also, the block is checked for cracks.