Ugrade to a 360

[GatorBate]

I want to replace my 305 in my 81 CJ5 with a 360. what year do I need to look for or will any of them work
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[Busted Knuckles]

Im guessing you have a typo in your post and you have a AMC 304 ..

They interchange, but you need the balancer and flywheel from the 360 to stay with the 360, they are balanced differently. Otherwise its a simple swap.

 

[GatorBate]

Re: Upgrade to a 360

what was i thinking, yes i meant AMC 304 .
So when I go looking through the wreaking yards for a 360 do I only want AMC 360s or will any 360 engine from a jeep Cherokee work. I know you can get adapter kits to make almost any thing fit, But I would like a direct replacement for the AMC 304 .

 

[Busted Knuckles]

Any 360 from any AMC built vehicle will work, nothing needs to be adapted, its a bolt in, exactly as it came out. Dimensionaly they are exactly the same, everything interchanges, including your accessories, just not the balancer and flywheel/flexplate. So yes, a direct replacement.

The older the motor the better as far as HP is concerned, if youre not going to rebuild it.

 

[GatorBate]

Thanks for the info. I just went to Wiki to see what they had to say. looks like in late 1970 and early 71 the 360 was sporting 10.5:1 compression. From late 71 to the last one built by AMC in 91 they had 8.5:1. Thanks again.

I passed a wreaking yard today, they had four or five older Cherokee on the front row and it got me thinking. mmm... summer time project.

 

[Busted Knuckles]

One of my currnet CJs, I bougth with a 360 in it, its an 83, the motor was 1971, it was a breather, the jeep was more muscle car, than 4x4. Ive never wheeled it because I scared of screwing it up. Ive got several other jeeps for going off road, its been my "trailer queen".

I ended up pulling the motor and selling it, so its "engineless" right now, and I cant decide what to do with it ! I pulled the motor to put a small chevy in it, but now Im thinking about putting it back to stock. Its almost bone stock right now with the origianl paint.

 

[mikey4her]

I am upgrading my 83'CJ7 from a AMC 258 i6 / 4.2l with a TF999 Transmission to an amc 360 with the TF999 auto Transmission . I am really clownfused. I thought that the AMC 258 i6 / 4.2l flexplate and the 360 were different but when I went to O'Reilly auto parts to order the new flexplate the part # for the AMC 258 i6 / 4.2l flexplate that matches 999 tranny is the same as the part # for the 360 flexplate that matche the999 tranny. Why? and if the tourq converter act as the flywheel then will I be ok if I use the converter that was on the AMC 258 i6 / 4.2l with the 360. Also some info says the flexplate is balanced neutral. that would explane most but raises the questions about the tourq conv. I saved the tourq convert from the 86' grand cherokee that donated the 360 but I can't find the flexplate that was on the 360. Do you think I should use the convert from the AMC 258 i6 / 4.2l combo or the 360 combo and will I need to order the new flexplate or just use the AMC 258 i6 / 4.2l flexplate. Thanks for any advice...

 

[GatorBate]

Busted Knuckles have you ran any of the later 360s in your CJs. It looks like the 71 360 was putting out around 365 FT/lbs of torque where as the latter ones were around 278 Ft/Lbs that is still about 58 lbs more than the AMC 304 . Then there are the straight 6s, lighter engine and sometimes as much torque than the AMC 304 . I guess I'm just curious what everyone's opinion is, who have ran the 360 in the CJ5 . Is it really worth it or do you just end up with a hot Trailer Queen that tears up drive trains when it hits the dirt.

 

[Busted Knuckles]

Busted Knuckles have you ran any of the later 360s in your CJs. It looks like the 71 360 was putting out around 365 FT/lbs of torque where as the latter ones were around 278 Ft/Lbs that is still about 58 lbs more than the AMC 304 . Then there are the straight 6s, lighter engine and sometimes as much torque than the AMC 304 . I guess I'm just curious what everyone's opinion is, who have ran the 360 in the CJ5 . Is it really worth it or do you just end up with a hot Trailer Queen that tears up drive trains when it hits the dirt.

Yes, Ive had newer 360s in a 7, but not stock, they always got a cam, intake, and headers, so none have been "pooches". 360 if fine in CJ, just dont "stand on it" if your worried about breaking stuff.

Id say the numbers dont really relate to the real world feel that much. I literally cant stand to drive a semi-stock AMC 258 i6 / 4.2l , let alone a bone stock AMC 258 i6 / 4.2l . I do have a 4.0L in my cherokee Im ok with as an "economy" car. If your on the fence, just keep the AMC 304 . Dont pull a AMC 304 to replace it with a AMC 258 i6 / 4.2l , very bad move. If youd like a little more torque and HP, throw a set of headers on the AMC 304 , that really wakes them up, that and an HEI distributor. If you want more power than that, then add a 4bbl.

One other note, the 4bbl on a AMC 304 does little if it does not have headers on it first.

 

[Busted Knuckles]

I am upgrading my 83'CJ7 from a AMC 258 i6 / 4.2l with a TF999 Transmission to an amc 360 with the TF999 auto Transmission . I am really clownfused. I thought that the AMC 258 i6 / 4.2l flexplate and the 360 were different but when I went to O'Reilly auto parts to order the new flexplate the part # for the AMC 258 i6 / 4.2l flexplate that matches 999 tranny is the same as the part # for the 360 flexplate that matche the999 tranny. Why? and if the tourq converter act as the flywheel then will I be ok if I use the converter that was on the AMC 258 i6 / 4.2l with the 360. Also some info says the flexplate is balanced neutral. that would explane most but raises the questions about the tourq conv. I saved the tourq convert from the 86' grand cherokee that donated the 360 but I can't find the flexplate that was on the 360. Do you think I should use the convert from the AMC 258 i6 / 4.2l combo or the 360 combo and will I need to order the new flexplate or just use the AMC 258 i6 / 4.2l flexplate. Thanks for any advice...

Thats a busy post...Im in the middle of a move, or Id have the answer to youre question, I dont know where my "books" are right now. Off the top of my head, I dont know the answer. Ive always migrated motors with their repsective flexplate/flywheel, and in this case, I understand you misplaced yours, but the numbers are the same as your AMC 258 i6 / 4.2l . That could be, but I cant verify, maybe somebody else will see this, or at least consider this a "bump" back up to the top.

 

[GatorBate]

Exultant, that is just the info i was looking for. I wish more people would have weight in on this, But from reading other threads I think that your experience is consistence with everyone else's opinions.
What cam are you using in your 360?
I have a some friends who are into rock crawling. Their advice is to put in an automatic Transmission like Mikey4her is doing (I like that name). Then you avoid tearing up the drive train by dumping the clutch, where most damage occurs. Unfortunately I like the old four speed standard. But that may change with time and experience.

 

[Busted Knuckles]

Exultant, that is just the info i was looking for. I wish more people would have weight in on this, But from reading other threads I think that your experience is consistence with everyone else's opinions.
What cam are you using in your 360?
I have a some friends who are into rock crawling. Their advice is to put in an automatic Transmission like Mikey4her is doing (I like that name). Then you avoid tearing up the drive train by dumping the clutch, where most damage occurs. Unfortunately I like the old four speed standard. But that may change with time and experience.

I used to run a crane "fireball" cam, keep in mind, I live in the "flat lands" we do no hill climbing or moutains, just mud, and I liked powering through things. A crane fireball is more of street strip cam, than an "Jeep" cam. I would not recommend it for your area (wasatch mountians?). Pick your favorite cam company, and buy the " RV and Towing" cam, will give you the most torque and some HP. The stock AMC came is fine for all around use, and as long as it does not have any "flat" lobes (which Ive never seen on an AMC 8), Id just run that. Maybe add a double rollter timing chain with the cam a Zero degrees, not advanced or retarded. Chances are your timing chain is stretched out, unless its been replaced. Same if you are buying a used motor.

Here's some, click on them to read the cam characteristics:

Products > Automotive > Camshafts > AMC 290-401 V8 66-91 > Hydraulic Flat Tappet

 

[mikey4her]

Thanks, I am still researching it. I think the flexplate is balanced neutral and the balance may be in the tourq conv. I have one for both motors. What do you think?

 

[Busted Knuckles]

Thanks, I am still researching it. I think the flexplate is balanced neutral and the balance may be in the tourq conv. I have one for both motors. What do you think?

I might be able to get you an answer tomorrow, I saw one of my interchage books today, while doing some clean up at the other place. We are not done moving...but off the top of my head, I dont remember, when I was younger, I could remember all these details, but now days, it all just flows together...

 

[mikey4her]

I think I got it now. I found my flexplate for the amc 360 that i had. The reason the part# was the same at some parts houses is that they don't ask if the 360 is amc or chrysler. the chrysler v8 is neutral balance flexplate and it is the same as the I6 AMC 258 i6 / 4.2l . I just had to connect all the dots. got the 360 in this weekend and bolted up just need to workout the motor mounts thanks.

 

[mikey4her]

The up grade is moving forward again. got my motor mounts and the 360 is bolted down and married to the tranny. the crankshaft is not center of the chassis. it is aout 3/4" closer to the driver side of the cassis rail. Should it be centerd. and I put the 360 in with the automatic. the shift linkage is all over the stock exaughst. how to modifiy? Thanks.