Jump to content

4.0 swap in 86 MJ

Recommended Posts

well I started taking apart the XJ (DAMN IT carpooler will be leaving sooner then expected)

and I saw som major difference with both trucks


for starter the piece that goes above the rad is not the same as the one originaly on the MJ and the XJ one will not fit without major fabing


second the rad doesn't fit between the fender without again some major cuting


I need advice from people who have done this before please

Ill be pulling the engine tommorow or the next day and will need to fit everything around it verry soon



Link to comment
Share on other sites

If you had read some of the previous discussions on this, you would have discovered that this swap is generally NOT recommended. You don't have to cut any fenders, but you do have to replace the complete inner front radiator support section to accommodate the wider 4..0L radiator. In addition, many people report that the firewall has to be cut or hammered to fit the 4.0L engine into the engine bay. (This part is not 100% -- it may be that late '86s were built using the same firewall that came on the 87 and newer vehicles.)


This is why the usual advice when someone asks about replacing a 2.8L is to drop in a Chevy 3.4L.


Don't know what you mean by "major fabbing." You need to swap the radiator support structure. That's a nuisance, but it's a straightforward swap and does not require any custom fabrication.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...