1991 to 1999 engine swap

[501mach1]

would like to know if anyone knows the pros and cons of swapping a 1999 4.0 explorer engine into a 1991 explorer .if necessary i can use all of the 1991 electronics since they are completely different.the '99 also has a egr that the '91 doesn't .will this spark knock without one .any comments will be greatly appreciated .

 

[410Fortune]

Do a search, this exact topic was just posted yesterday by a guy who just put a 99 4.0L into his 91 Explorer

Yes it will work
Yes you keep everything from the 91, the only thing you use from the 99 block is the long block and lower intake....