Would NGK Tr6's work in my truck? I see some KR (2-7) at heavy part throttle acceleration and just a touch ,like 1* at wot sometimes. I am wondering if the tr-6, being a colder plug would help or would they be too cold. I think the milled heads has something to do with it. Maybe not though.

 

i wouldnt run tr6's unless you are running boost or nitrous. ngk tr55ix's will work. 7164 is the part#. i would be looking at your timing to.

 

Tried some TR6's just for kicks to see if it would affect KR, and it did not. They are still in the truck and runs just fine, at least no worse than the stock ones were with 68k on them. I put em in and made a hard run and pulled them out to see and they looked Light tan color no black. With the truck in park I can rev any speed with 0* Kr, I guess that is because there is no load. Any ideas?