HO 242 / 258 swap

Ok part of this involves an XJ so I guess that counts. I have a 93 2wd XJ that just fell into my hands. My buddy just bought an 88 YJ in a sad state of disrepair. How much of a P.I.T.A. am I looking at for the HO 4.0 into the 88 YJ. I know that all of the electronics have to go with the 4.0, but is it worth it. The guy that he bought it from says that the 258 was rebuilt in 2000, but he's a crack head so who really knows? Am I better off rebuilding the carb on the 258 and chasing down all of the other little gremlins? either way he is going to kick some money my way, but if I do the swap I get a 258 crank for my stroker project (in the distant future). Any ideas would be great, also pros and cons would help too.

TIA,
Neil

I was just looking into 4.0 swaps my self
http://www.cjoffroad.com/
check out the forums there...

Thanks for the link. looks like a daunting task. Took me an hour alone sifting through the garbage to find what I was looking for. I don't think that there would be any actual fitment issues with the 4.0. I think that if I am going to do this I will swap put the whole power-train and just have new driveshafts made. that looks to be the easiest route. I'm still not sure if it's worth it though.

Thanks,
Neil

Don't bother with the BBD, its junk. Do a compression test on the 258, and check the bearings. If it's healthy, just drop the 4.0 head and mpi on it. It's a very easy swap. Things to consider:
1. Check the 4.0 head for overlap on the 258 block. The water jackets on the exhaust side must not be exposed.
2. The yj has a mechanical speedo, the mpi uses an electric one. The tach signal is different too. Just swap to newer yj gauges.
3. The mpi needs an electric fuel pump, either swap in a newer tank or use a fuel pump from an 80's F150(an E2000 works great).
The other option is to swap to a Motorcraft 2100 carb.

Another thing to consider, that I forgot to mention is this is a California vehicle and I have smog laws to consider. I know that the mpi is a cleaner system, but most California smog techs. are retards and if it dosn't look like the picture in there book it will fail. Do you know if the motorcraft 2100 has a CARB EO number?

Thanks
Neil

Ok, I checked the compression on the 258 the numbers were 90;95;120;95;100;90. So it doesn't look so good for the 258. Here is what he is offering me to do the job, a 1998 Yamaha Blaster 4 wheeler, the old 258 motor and a couple of hundred bucks. Is it worth it? I am supplying the 4.0 and AW4 and the labor. The 4.0 and AW4 were free from a 2wd Cherokee that was given to me. The quad is in ok shape, it might need a few things (small mechanical) and it's pretty ugly. Am I better off offering to rebuild the 258? I just don't want this to become a never ending project. (My Jeep is enough for me.) I also don't want to get screwed on this deal. Any advice would help thanks.

Neil