crossmember

[jason21]

i plan on puting a 360 in my jeep this winter. i noticed my crossmember is set further back with the i line 6. does anybody know if u have to move it further forward or, can i leave it wear it is?

[dnixon]

if you are going with factory gear then it shouldn't be a problem. The frames, at least mine, had two sets of holes. One set for the 360 combo's and one set for the I6 combos. SO you might want to crawl under and check it out but I don't think you will have a problem if you have the additional factory holes. Good luck.

[jason21]

i do have extra factory holes further forward then my crossmember now. i was wondering if i should put it there or leave it were it is.

[jeepguzzi]

You have a choice. Which tranny/Tcase are you going to use?

The 360 sits further forward than the 258. The motormount towers on the frame are different and use different mounting holes (which are already there). They also use a couple of the same holes. Grab the 360 frame mounts from a donor FSJ.

You need to decide what to do about a radiator. I cut my support like the factory did, then had a 3 core 258 radiator merged with the mounting brackets for a 360 rad. I may end up finding a different hose if the stock one doesn't work out.

The fuel lines enter the engine bay on different sides. Grab the line from the donor, if possible.

If you are using an auto trans, simply move the crossmember to the correct set of holes. Get the driveshafts from a donor FSJ, or make new ones.

If you have a manual tranny from the 258, you have a choice. You could go find an auto tranny. Or, simply bolt the 258 tranny to the 360. (You'll need a 360 flywheel) You will also have to fabricate clutch linkages. You will need new driveshafts. This will move the shift lever forward in the cab about 4". Notch the floor and then you will need to figure out something for the lever boots. You would also need to fabricate some sort of crossmember extension or custom crossmember if you choose this route.It can be made to work, though.Unfortunately for me, this is the route I took.

Or, you can find an adapter that goes between the bellhousing and the manual tranny. If you do this, the clutch linkages may be easier to figure out, but you will need to get a long input shaft for the tranny. Your old driveshafts should still work.

If you have one of the later 258's with the computer controlled carb, the easiest solution that I found was to swap the engine wiring harness with one from a 360 of a comparable year. They will plug right in, so it's a fairly easy switch. The 360 will not fire if you try to use the 258/computer harness.

If I had to do it over again, I would find an auto tranny and not have so much fab work to do. I may yet end up going that route, but now that I have money in new driveshaft,clutch,radiator and stuff, it would cost a bunch. I'll drive it like this, but if my engineering and jury rigging fail,(which could happen easily) I'll be looking for a Chrysler tranny to go in front of the NP208.

[ September 21, 2004, 12:52 PM: Message edited by: jeepguzzi ]

[KYJ10]

All holes are there for any configuration jeep used at the time. The holes are there for the motoer mounts, they are there for the crossmember. Just depepnds on what combo you run. It's really just a matter of getting everything together and figuring out where they go. I swaped in the entire engine/tranny/tcase from a j20 into my 258 j10. Was simple. As mentioned, get the motor mounts from the donor. Get the crossmember also, as there may be some parts of it you will need depending on what you combo you choose.

[jason21]

i already have a np208 in it and has the 727 trany thanks for the input