swapping in a newer 4.0

[Richard]

Hi, I was recently offered an 2000XJ short block for a real good price and was wondering if I could swap it into a 88 XJ, and what head would be best for this swap.

[4.whoa]

That depends. From the hg down its basically the same engine. You don't HAVE to change the head, but if you do you NEED the int/ exh manifolds too. The renix (mani)ports are too low to match the newer heads. Then if you do swap you need to adapt your fuel rail- different fuel line connections/mounts ,and tps. Several people here have done it , its just more involved then swap'n.

[Richard]

so then basically all XJ block ar physically the same on the outside? just hook up the old mounts and brackets and such and thow it in?

[Muad'Dib]

That block is going to be missing the Knock Sensor bung too.. so you will want to get it drilled and tapped for that or leave the knock sensor disconnected (i wouldnt recommend that but some people do it).

[Richard]

thanks guys. looks like i will be building a stroker then on the 2000 short block to swap it in the 88 xj then

[gonridnu]

If you look at the projects section I did a thread on putting a newer motor in a Renix era XJ. I used the later H.O. head as well so if you are contemplating that as well jump on over there and it is pretty much all laid out for you.