258 to 360 conversion

[jeepstruck]

I have a 1980 J-10 pickup w/258 in it. I am going to change the engine to a 360. I thought that I had done all the research that I needed to do. I purchased an old Cherokee that had a 360 in it. I pulled everything from the radiator to the trans. and thought that I was ready for the swap. My 258 has a 4-speed trans. with it and I would like to keep it. The cherokee had an automatic trans. I have been told that my 4-speed trans. will work with the 360. I hope that is correct but, someone told me yesterday that it would not work. Please help me! Could somebody out there tell me what I need to do to make this swap. Thanks for any adice.

[joe]

You'll need a 360 flywheel(not flexplate) for a manual trans plus the bellhousing from a 360 and the input shaft for the trans from a 360. The V8's sit farther forward than the sixes so the input shaft/bellhousing is shorter on the sixes(longer on the V8's).

[jeepstruck]

Thanks for the advice. Do you know where I might find those parts. I have the flywheel. I guess all I need now is the input shaft and bellhousing.

[joe]

I'm not 100% sure here but I don't think you can use the 258's flywheel on a 360. Maybe you can get it re-balanced for the 360 though? Hopefully some else will jump in here and let ya know for sure.
The parts you need are still avail new from various vendors but where to find used stuff in NC I wouldn't know.

[jeepstruck]

I purchased a resurfaced flywheel for a 360. I am willing to buy the parts brand new. Do you know where I would find them? Is it going to be an aftermarket or dealer item? Thanks again!

[TexasJ10]

I thought the bellhousings were the same for the 258 and 360, but that an adapter/spacer was used after the bellhousing but before the tranny to accomodate the longer input shaft. I'm not sure about this though and yield to others here. Anyway, a bellhousing for a t18 is on ebay at the following link
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1840447231

You might find the input shaft by placing a request in the parts wanted section of this forum.

[ July 02, 2002, 10:32 AM: Message edited by: TexasJ10 ]

[UnkleMunky]

You forgot an important step: anyone doing a 258->360 swap needs to send ME their 258 stuff! smile.gif heeheee! I'd even take that T176 if you didn't want it!!! smile.gif

I can't answer the question of what all you need beyond what you've researched, as I've never wanted to go the 6->8 route, but yes, the T176 "was" mated behind V8s, and can hold up to it......it's just not a "bulletproof" tranny that would be nice in a Jeep. If you treat it well, it'll probably be just fine behind a 360.

[jeepstruck]

I Have enjoyed my 258. It's just time for a change. I've had this truck for 22 years and always wanted one with a 360. I did make one mistake though. In 1984, I put a 1982 258 in it instead of rebuilding the 1980. I don't know why jeep ever put those plastic valve covers on. It's been leaking for 18 long years. The 258 is a **** good (and strong) engine. I'm ready for a little more power and I don't think I'll get any worse gas milage. I might even get a little better. A J-10 with 35" tires is a lot for that little tired 258.

[joe]

Originally posted by jeepstruck:
I purchased a resurfaced flywheel for a 360. I am willing to buy the parts brand new. Do you know where I would find them? Is it going to be an aftermarket or dealer item? Thanks again!It'd be aftermarket from someone like Novaks or another gear vendor. You might try NAPA though and I would also check with ordering it through a local transmission shop, may be cheaper than Novaks. The 4sp in your J-10 "should" be a T-176. The T-18A's were only used in J-20's after 1979.

[K-Centre]

I can understand going from the 258 to the 360, just I wouldn't do it :D
Seriously, that is almost definitely the T176 4 speed behind the 258. To my knowledge they did use it behind the V8's but that it was kind of rare. If I recall, BitterSC was working on mating a 360 with the T176. Also, Panther pulled a T176 from behind his 360 in favor of the T18. You should try to get hold of one of them as they have direct experience with the transmission with a V8 and may be able to give you more of the info you are looking for (what's needed, dimensions, etc.)

[UnkleMunky]

Originally posted by K-Centre:
I can understand going from the 258 to the 360, just I wouldn't do it :D
My thinking exactly....I wasn't questioning you doing it....just jiving ya a bit and enjoying the 258s where lots of people just skip right to V8....glad you know how good a 258 can be!

Take care...

[JEEPGUZZZI]

I think you can use the 258 bellhousing without the adapter, just moves the tranny forward about 4". The gear shift will still work, just further forward. You will need to do something about the clutch linkages, the parts are no longer available. Other issues will be the radiator and it's position, getting 360 motor mounts for the frame, and wiring. My 1985 j10 had a 258 with a computer for the carb. I don't think this is an issue for you. I found a new flywheel from Specialty Jeep Parts. It is unlikely that a 258 flywheel can be made into a decent 360 flywheel. Everywhere I asked about this said no. :mad: One other thing, the fuel lines come into the engine compartment on opposite sides.

[mdill]

I from what I have seen, the bellhousing is the same,
input shaft is different and there is a spacer between
the trans and bellhousing. I beleive you still need to move
the trany, meaning drive shafts lenghts change along with
shift linkages.
Really think it over and be sure you really want a 360,
the 258 is a heck of a motor (Not real good with 35"
tire agreed), but the 4.0L are pretty common, lots of
after market support for performance parts and a
heck of a lot easier swap. (thank you bob tail jeep guys)
If you are willing to spend some $ a stroker 4.0L can
be had in crate form from the web.

Good luck with it either way.

[matt0481]

I called the local auto parts store and asked them to look up the flywheel for a '78 Cherokee. The part #'s are the same for both the 258 & 360.

[JEEPGUZZZI]

[ July 03, 2002, 08:51 AM: Message edited by: JEEPGUZZZI ]

[JEEPGUZZZI]

I called the local auto parts store and asked them to look up the flywheel for a '78 Cherokee. The part #'s are the same for both the 258 & 360.

O.K. Lets consider the source. I had both flywheels side by side, and I am sure they are different. Maybe your parts guy looked up flexplates or something. Maybe he looked up chrysler 360 vs. 4.0. Because we all know these are Chrysler 360's in here,RIGHT? :rolleyes: ;)
The way an inline 6cyl. is balanced is way different from the way a v-8 flywheel is balanced.

[jeepstruck]

Originally posted by mdill:
I from what I have seen, the bellhousing is the same,
input shaft is different and there is a spacer between
the trans and bellhousing. I beleive you still need to move
the trany, meaning drive shafts lenghts change along with
shift linkages.
Really think it over and be sure you really want a 360,
the 258 is a heck of a motor (Not real good with 35"
tire agreed), but the 4.0L are pretty common, lots of
after market support for performance parts and a
heck of a lot easier swap. (thank you bob tail jeep guys)
If you are willing to spend some $ a stroker 4.0L can
be had in crate form from the web.

Good luck with it either way.I just figured that if I'm going to drop at least $2,000 on an engine that I might as well put a V-8 in.

[joe]

Originally posted by matt0481:
I called the local auto parts store and asked them to look up the flywheel for a '78 Cherokee. The part #'s are the same for both the 258 & 360.The AMC p/n's are certainly different for the 258 and 360 flywheels.

[Towtruck]

I'm in process on a 727/208 to 4-speed swap behind my '81 360 V-8 J-10. I initially purchased a complete short shaft T-176 driveline from an '80 258 six cylinder truck thinking it would drop right in. Well, it can be made to fit, but it's not as simple as I thought. As someone mentioned earlier, the bellhousing location for the V-8 ends up about five inches farther forward than for the six. So the clutch linkage between the pedal and the clutch is different. Also, the frame rails do not have a set of predrilled holes that are far enough forward to relocate the transmission cross member for the short shaft T-176. In fact, a new set of holes would have to be located roughly where the longitudinal frame rails start to sweep upward...in fact, Im not sure there's even room to drill new ones and still keep the trans cross member at the proper height. So you'd have to fabricate something for that, I guess.

Anyway, given the expected shifter interfere with the under-dash AC, the required mods to the transfer case linkage (minor), redrilling for the cross member, and the clutch linkage mods, I abandoned this approach. Sold the short shaft T-176 with very little trouble to a CJ guy...they apparently like them in place of T-4/T-5.

At the moment I have a long shaft (13.5 inch stickout) T-18/D-20 and passenger side drop Dana 44 from a J-20 sitting on garage floor. It uses an aluminum 4.75 inch spacer between bellhousing and transfer case. Along the way I also purchased PANTHER's left over long shaft T-176 with a similar, but slightly different length spacer. If I like the T-18, the long shaft T-176 and spacer will be for sale....along with all the other leftovers/spares: bellhousing (identical for six and V-8), the six cylinder pedal setup, two 727's, two 208's, and a left over driver side drop Dana 44.

Finally, the 6 and V-8 flywheels are indeed different (V-8 item is thicker and heavier, and has a balance weight cast into it). While I didn't specifically check, I suspect the V-8 bolt pattern is indexed to the crank because of that balance weight. Best deal I've found for a new 360 flywheel is at 1-800-923-JEEP...$125.

Regards, Eric

[jeepstruck]

It sounds like all I need to do is get a longer input shaft and the right size spacer for the bellhousing. I talked to a local trans. shop yesterday and he said the parts are available and he should be able to get them. My question is: If I get the longer shaft and the correct spacer, why will I have to move the trans. forward?

[waggin'ear]

Get Back to work!

[jeepstruck]

I'm working ;)

[JEEPGUZZZI]

If you use the spacer, you do not have to move the tranny.

[Towtruck]

I was referring to problems with bolting a short shaft T-176 directly to a V-8 bellhousing. If you have long shaft and spacer, you're in business. The cross member holes are already there.

But a word of caution about converting a short shaft T-176 to a long shaft. I tried that route myself. The gear ratios are different for the long and short shaft transmissions. So you can't just stab in a long input shaft. The local gear place here in Fort Worth advised I'd also have to change out the guts of the transmission (believe it's the main cluster). Get's rather expensive.

[jeepstruck]

O.K., let me know when your ready to sell that T-176 Trans.

[Panther]

Hey Eric, thanks for your patience with the T176 man. I'm sorry it's taking so long, things have been kinda nuts lately.

Also Eric, is right, it's best to try and find a doner T176 for 360 for simplicity.
The bell housing spacer serves a few purposes from what I could see.
1. Position the shifter in the same location for either the T18 or T176 (80+ I suppose)
2. Position cross member to the forwardmost access holes on the frame
And like Eric said, it might require a custom crossmember if you use the 6cyl T176 because the stock crossmember would be moved forward on the frame.

I honestly think all jeep bell housings are the same for AMC. There are different notches for different trans bolt patterns but no real different for either 6 or 8 cyl.

Another option would be the T18. Choices are either the 79 or older T18 with Dana 20 or 80+ T18 with NP208 found in the J20. Anyway I did a little investigation on this swap and you can see the post here Swapping T18 in place of T176 (http://www.ifsja.org/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=2&t=008012)

I went with the T18/208 and you can follow my story here The T18 story..... (http://www.ifsja.org/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=3&t=005145)

Anyway, I hope that helps. Don't mean to confuse or overwhelm but show some options. To keep it simple, it would be easiest to find a T176 for the 360 with BH spacer.
Lee

[bfeller]

Call Glen's Salvage yard in Durham NC. He has had a J-truck with a 360 and a manual tranny in it for the last year or so.

[Towtruck]

PANTHER, How is the T-18 working for you on the street? I'm curious if you use first gear very much. That's been my main reservation with the T-18. My truck is primarily a tow vehicle, and occasional commuter with 30 inch street tires/3.31 gears. Seems like that low first gear might be rarely used. On the other hand, everyone says the 176 won't cut it for long when towing. Anyway, I'm interested in your experience. Regards, Eric

[jeepstruck]

Originally posted by bfeller:
Call Glen's Salvage yard in Durham NC. He has had a J-truck with a 360 and a manual tranny in it for the last year or so.You wouldn't happen to have that phone number would you. I looked in the phone book and called information. I could not find the number. That would be great if I could find what I need in Durham. Thanks!!

[Panther]

I love the T18. With the 3.31s and 33s I use 1st gear most of the time.
2nd seems close to what the first gear was in the T176. I spend a lot of time in traffic driving 5 mph so the T18 1st gear is great. Some like the T18, some don't but I like it.

[joe]

If Lee(Panther) is driving around town in 1st gear I suspect he has the later close ratio T-18.
"T-18" is sorta getting to be a generic term for the "two" different models. It gets a bit confusing so make "sure" you know what you're shopping for and what you'll be getting.
All T-18's started out as wide ratio models with a 6.32:1 first gear(granny low). Later(late60's or so?) the T-18's changed to a close ratio gear set with first gear now being 4.02 and the old T-18 wide ratio tannies now became the T-18A's.
Bottom line: all T-18A's are the wide ratio 6.32 1st gear trannies but T-18's can be either the wide or close ratio depending on what year it was built. Early are wide ratio, later are close ratio.
If Lee is experiencing similar 1st gear driving characteristics that he had with his previous T-176 it's prolly the later T-18 close ratio that he has. The T-176 1st gears were similar(3.82 or 3.52 depending on the motor it was behind).
You won't be driving around town much in first gear with the wide ratio trans but it's excellent for crawling or launching boats on steep boat ramps etc. Unless you offroad, launch boats or move heavy loads you may never ever even use first gear with a wide ratio T-18/T-18A tranny. Cool to have when you need it though smile.gif

[Panther]

Hey Joe, great info.
I didn't know the T176 had different ratios with different motors, I suspect the 3.52 was for the 360 and 3.82 for 258?
From what I understand the T18 in the J20 after 80 only had the wide ratio 6.32 and mine is definately a granny gear. I have to be at a complete stop to put it into first and I'm not gona beat anyone off the line in first :D :D :D I do start in 2nd also but I like to start in first because you can release clutch w/o apply throttle, don't like to ride the clutch. Also my scrambler has the Ford version wide ratio T18 but with 4.56 gears first is useless on the street. I think I'm able to get away with using 1st in the chero because of the taller gears (3.31) and 33" tires (tho they do run kinda small for 33). I was able to use 1st in the scrambler when it had 33's and 2.73 gears also.
It might sound strange but I actually wanted the T18 for street, I do spend a lot of time crawlin in traffic (5 mph) and can take me an hour and a half to go 10 miles (sometimes worse). I do plan on flat towing also and didn't want to have to ride the clutch when towing. But with stock tires, 3.31s and T18, 1st will probably be useless.

[joe]

Originally posted by Panther:
I didn't know the T176 had different ratios with different motors, I suspect the 3.52 was for the 360 and 3.82 for 258? Yup correct.

From what I understand the T18 in the J20 after 80 only had the wide ratio 6.32 and mine is definately a granny gear. Correct but yours is actually labeled the T-18A if came from an 80 J-20. I think the name switched from T-18 for the wide ratio version to T-18A around 1968 or so.
I think I'm able to get away with using 1st in the chero because of the taller gears (3.31) and 33" tires (tho they do run kinda small for 33). With that set up I could see where you'd get some use out of first on the street.