I have a 3.7 in 1500 truck 180,000 miles no trouble,but a 2003 durango, with a 4.7 ,at 118000 bit the dust on vacation. I went to a local junkyard to get a used head, owner said there's 16 durango's in a row ,none wrecked either transmission or engines bad,I pulled heads off 5 different ones,all...