thanks for the reply, i was taking the overdrive on and off, off when i would be going up an incline, i think it was a combo of running lean and also the extra hot plug in number 3 cylinder, its strange how it worked out, the cylinder that was running lean by fate got the only wrong plug in the batch.
i have since cleaned the mass air, throttle body and the egr, added an additive to the fuel and filled up with 93 oct as even the replacement engine was pinging some in overdrive without the trailer hooked up.
now the truck is not pinging and runs very well. i am keeping my fingers crossed, i am leaving again for florida the day after thanksgiving and plan on adding another bottle of additive and running nothing but 93 on the way down and taking it easy on the little guy just staying at 55-60 instead of trying to keep it a 70.
hopefully it will travel with no problems now.

 

It was caused by a lean condition the ping was pre detonation(spark knock). Either caused by a bad injector or a vacuum leak.

 

While I have a different motor in my Ranger, it does much better with premium fuel. I get about 1.8 more MPG, which makes a big difference when you drive 300+ miles a day.

 

I put 2000# behind my 3.0 ranger once and it felt like I was pulling the boat anchor for the titantic. These rangers are not designed to pull weight like that for long periods of time if you need to pull the rideing mower across town thats one thing. Do I think the load burnt a hole in your piston, absolutly not unless it was running hot very hot or it had the wrong plugs. From my experence the 3.0 is darn near bullet proof if properly taken care of. I bought my 96 new it now has 210,000 on it and I have not had to do anything to the engine (not even valve cover gaskets) The part I would be worried about is the transmission (if it is an automatic) pulling a load when it shifts back and forth multiple times that builds heat and that is not good take it out of O/D for sure if you must pull a load. (if it a auto trans)