Can someone explain why some after market parts for the 4.0 do not include the 91 and 92 model years? I have a 92 that has the typical leakey valve cover. I decided to replace it with an aluminum cover, but I found most catalogs only offer covers for 93-04. After looking at other items there were quite a few that also skip the 91-92 years. Some of those parts include cap and rotors, spark plug wires, and headers. The thing that I find really odd is that I have found some brands that say the same parts listed above work for all years 91-04. If there are no differences, why would these manufactures and resellers give up sales for those two years? So, what are the differences between the 91-92 and the 93-04 4.0 engines? Thanks!
- posted
19 years ago