Just finished the body and suspension on my 82 Chief - I need a new motor now. The current 360 is bunk, its got a bad lifter/valve noise and is a pig and pain to tune. I would really like a bulletproof 4.0l or 4.2l to make this thing reliable (power is less of a concern over mileage and economy). What swap is easiest - use a 258 and matching trans mated up to current tcase of pull the trans/motor/tcase from an XJ and put it in? Can anyone lend my some insight? Thanks a ton.
06-27-2013 10:55 AM
If it were me, I'd rebuild the 360. However, if you are set on putting in a 6, I'd go with a fuel injected 4.0 The 4.0 shares the same bellhousing bolt patern as your 360, so it will bolt to your current transmission(might need a different flex plate though). Then it would just be a matter of new motor mounts and some wiring.
And, here's some interesting info, the 4.0 makes 180-190 HP. The 360 used from 78-91, only made 160 HP.
06-27-2013 11:13 AM
I have a 4.8 stroker fully forged,ported,balanced,solid lifter cam etc setup for the single turbo/intercooler on my WJ. Also own my GWagon with 360. The 360 economy stinks 13-14mpg at best. The 4.8 in the lifted WJ gets 23-24 hwy, 16 city in traffic with AC loaded up etc. I plan to redo the top end/cam/heads on my 360 and eventually add computer controlled timing and injection. Accompanied with an overdrive it should get 18 hwy and likely 13 city. I think 20mpg will be pushing it with a gas engine as the truck has the aerodynamics of a cinder block. If you can score an injected 4.0 thats in good shape go that route. The injection is easily tune-able for anything you want to do. ( I have someone who is amazing with the Chrysler PCM) In that big jeep though your going to wish it was a stroker quickly as the 4.0 in stock form in my WJ 4x4 got about 14mpg since new and maybe 16 hwy. Once I added the larger stroke/bore the boost in tq and tuning not only added a TON of power but increased the mileage immensely. Part of the gain was it was a CA emission truck and tuned terribly from the factory plus had 3 cats on it. Personally if you have a 360 that is rebuild able I would lean that route or snag an LS 4.8/5.3 driveline out of a GM rig and bolt it all in with the OD trans/PCM/T-Case. You will get near 20mpg and great power with either motor and the salvage yards near Austin I have spoken with will sell me the entire setup complete for <2k with under 30k miles on it. Hard to argue with 300+ hp/Overdrive/Injection for that price.
06-27-2013 12:09 PM
My j10 360 gets 15mpg hwy when it feels good. My 87 xj 4.0 2wd 210k gets 25mpg hwy.
My buddy just got a 94xj 4.0ho, with 301k, and horrible valve clatter, but has incredibly more power than my xj, which runs better. If you go with the 4.0, definetly get the ho version.
06-27-2013 06:57 PM
Definitely the route im thinking is the 92-94 HO 4.0l. My only concern is will it bolt right up and what else needs to be changed?
06-27-2013 08:42 PM
The only easy bolt in I know of is another 360. Going w/4.0, have you considered using the AW4 since it has overdrive? Gearing, tire size & lift are all factors too. My 81 cherokee w/t track w/258, auto, 3:31 gearing and running 31 inch tires got me 15 mpg, my XJs w/4.0, auto, 3:55 gears and 30 inch tires got 16 mpg w/3 inch lift & 17 mpg w/2 inch lift. My waggies w/360, auto, various gearing got 10-13, That's 65-70 mph. That's just my experiences but a consideration.
06-27-2013 08:52 PM
Its got the manual trans rights now, so I definitely dont want to convert to auto. Im just wondering if the t176 with long tailshaft and spacer will mate up to the 4.0L. This amc 360 is bagged, and a bulletproof 4.0l is defs a better plan.
06-28-2013 08:32 AM
I 2nd super98lsc. I have a 4 door 83 cherokee that had a 258, T176 and NP208. I added HEI dizzy, 4.0 head and 2100 2bbl carb. Once I changed the axles to WT and 3.?? from the 2.76 I had, I thought it was real good.
Now I kept the crank and piston rods from the 258 and built a 4.6 stoker. I am keeping my T176 for now and just need a bushing from Novac, and to drill/mount the CPS in the bell housing. If you go to a 6 cyl, you will need to do something with you engine frame mounts, move them fwd I think. Also the T176 you have on the 360 is a long shaft one, you will need to get a short shaft one from a 285, or find a AX-15 and the 231 xfr case, or a NV3550 ( I believe a NP208 xfr case will bolt right up to that one, thats what I am wating for, prices to come way down) that will mate right up to the 4.0
Right now I am going through the the 83 engine harness and a 91 cherokee engine harness to mate the two for my stroker install.
06-30-2013 02:51 PM
So if I dumped a 4.0l, ax15, 231 combo into this, would I need new driveshafts as well?