Originally Posted by WillysJeepScout
Q: I don't have the manual for this Jeep yet and didn't know it was a 4.0.H.O. I assume that is a Head modification because the CID is lower than my other Jeep. Does anyone have one and/or any tips for this particular engine as far as spark plug gap difference, Timing...Ect...?
All six cylinder YJs from 1991 & newer are 4.0L (242 CID) "High Output" engines with Mopar fuel injection.
Spark plugs are Autolite AP985 & the gap is 0.035"