4.0 ohv year to year differences

[Connorrexilius]

I have two separate questions here.

1. I have heard that the heads/head gaskets were updated around 94 on the ohv 4.0, wanting to know if this is true. Looking to know if there were any "updates/improvements" during the run of the 4.0 ohv.

2. I'm probably going to swap another 4.0 into my 92 ranger, the current engine has basically called it quits. I want to know what years of ranger/explorer I can grab a 4.0 ohv from that will be 100% plug and play to my truck.

Any information is greatly appreciated!

 

[1TUFF92]

This will tell you all you need to know about the 4.0L.
http://www.therangerstation.com/tech_library/40rebuild.shtml