94 Dodge ram 4x4, runs super rough.

Our shop truck is giving me fits. In fact it has stumped 3 shops so far.

Here's the story.

Bought the truck for 400.00 dollars. Threw everything away except the cab and frame. Rebuilt the truck from the groumd up.

Got a good running 360 mag from a buddy and put it in. All was well.

Pops blew the trans cooler line and smoked the trans.

Had trans rebuilt by a local trany shop.

Shop calls and says trans is in but the truck wont run. ?????

I go down and look over the truck. Everything seems ok. Spark, cylinder pressure, fuel are all good.

Truck will fire and run normal but as soon as its up to temp it shutters VERY BAD. Undriveable bad.

Now not trans shutter, RPM flutter.

Trans shop sends it to their mechanic and two weeks go by. They cant fix it. Some deal was reached between pops and trans guy for money off the bill or some such. I forgot it was a while ago now.

Take the truck to my buddys shop. 4 days. He changed out a bunch of sensors and could not fix it. So we payed for the parts and towed the truck home.

Now i got sone time im wondering what the hell is wro g with this thing.

Talking to a buddy and he mentioned they had one where something in the gauge cluster was unsoldered, soldered it up and ran fine. (He cant remember what it was but said it was a dodge mini van.)
He also mentioned that the ECU in these trucks oftend crap out.

The strange thing is, it runs and drives great until it gets warm and BOOM, now your are looking to pull over right tue F now beacuse it seems like it will die at any second. (Some times it dies, some times it recovers)

Any ideas what the heck is wrong?

Pops would be very happy to be driving his fancy truck again. Thank you!