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4.0 Head swap

450 Views 4 Replies 3 Participants Last post by  **DONOTDELETE**
Well I found a whole 4.0 in a Junkyard, and was thinking about sticking it into my Jeep, when I found that it was a siezed engine. So anyways I'm taking the head off it pretty soon, what will be required to do the swap, and what benefits will I get? Thanks everybody- I promise to take pictures and do a write-up on the swap if I ever get it done!

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make sure the water jackets line up... and that the head bolts will fit.. that is about all i can say.. did you get the efi? if you did.. waay cool.

survival is instinct, but living takes guts
Why would I get the EFI? Will it work on the 4.2? I thought the computer wouldn't run it right since it would be missing so many sensors.

It is my understanding that the only intake for the 4.0 is the MPI unless you go aftermarket. Don't worry about the water ports, use the 4.2 head gasket and you won't have any problem. That is the way mine has been for the last 2 years. Get all the sensors, and the computer, and you will need to get a damper and pickup for the MPI unless you can get the 4.o flywheel and sensor to work on your 4.2

Enjoying Montana's Big Sky (& rocks & rivers & mountians etc, You get the picture.)
what does a 4.o flywheel have to do with a mpi swap into a 258?

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