jeep/AMC 360 questions

[hoobness]

so I ended up buying the 78 cj7 I was asking questions about weeks back. Been doing a lot of fixing since then. Still not registered yet since I still have work to do on it so I feel confident it won't leave me stranded. Anyway..

it has a 304 and the valve seals are leaking, some point I'll need to work the heads. Been doing a lot of reading and learned I can't just swap in a sbc 350 like I wanted with out replacing the driveline. Its an automatic with the quadratrac and offset AMC 20.
now I'm looking at replacing the 304 at some point with a 360 for the simplicity of install. I'd build the 360 in the garage and swap them when ready.

will any AMC 360 bolt right on in or does it have to be out of a jeep product?

thanks

 

[69jeepcj]

Cant give a for sure answer as Ive never looked into it. I would think though that a AMC360 is just that and is the same, small things like oil pan may be different. I don't see why you would need to change your drivetrain to run a sbc, I have one in my jeep and the only thing changed was the trans which was the 4spd that came in the car the engine came out of. You have a th400 trans but I believe the bolt pattern is AMC specific and dif than that of the sbc. A adapter would probably solve that issue. The 360 would be a simpler swap though.

 

[SteelHeadz]

Yes, the AMC 360 is a straight swap. If I remember correctly, I pulled mine out of a 79 Jeep Wagoneer. There's one thing you should look at before stabbing the engine in your jeep. I noticed on mine, there's a spacer on the rear of the crankshaft where the flywheel bolts into. You need to make sure you remove that spacer if it has one otherwise the trans won't completely bolt on flush with the engine. Other than that, most of all your AMC 304 parts will swap over to the AMC 360..

 

[hoobness]

I read the SBC 350 won't bolt to the AMC/gm th400 and any gm th400 that holds to the SBC 350 won't bolt to the quadratrac and replacing the quadratrac leaves you needing to replace the offset AMC 20. 360 sounds simpler and a lot cheaper in my.case

 

[69jeepcj]

That is true, but Advance Adapters sell adapters for just about any engine and trany combo you can think of. If you got an adapter to bolt your current trany to a SBC you wouldn't have to mess with the tcase at all. You are correct though that the 360 would be much simpler, straight bolt in.

 

[uberxj92]

The amc 304,360,401 are all the same block. So they will swap. You might look into putting efi on it. Help when flexed and help the mileage

 

[jps4jeep]

As mentioned, the amc 304 and 360 used in jeeps are idendical blocks, all the accessories will swap over and have the same bell housing pattern. That said, why bother swapping out the 304? the 304 is a great motor. the jeep 360 only made about 10 hp &ft/lb more than the 304 depending on the year.

Is the time moeny and labor involved worth it for a couple HP? The biggest problem with the 304 and 360 motors is that they were choked down with emissions crap and POS 2 bbl carbs that would not let the motor operate optimally. If it were me, I would finding a second set of heads, re-build them, valve seals are pretty easy and cheap to do. swap in either EFI or a well tuned 4 bbl carb and drive the **** out of it. I would definately not swap in a chevy 350. if I were swap any motor in, it would be a AMC 401.

 

[hoobness]

The valve seals are def leaking. And I have yet to comp test out leak down on it as I'm still battling a lot of other stuff before I put it on the road. I'm more or less exploring options that I know how will have to consider in the future.
All the emissions stuff is gone and I ripped out what wasn't. Has a holley 2 bbl 78xx on top, headmen headers into side pipes exiting before the rear wheels. Fun lil buggy in the neighborhood lol.
I agree w johnny about the 304 being plenty for such a lightweight buggy. Its very basic. I think it was a backwoods good time jeep for someone for a while based on where I've found mud and stuff...ie under the dash, caked in odd spots.
I need to get it on the road and quiet the exhaust a bit to get an idea of what direction to go in, either way I want a hot rod jeep i can blast around in the sand, dukes of hazard style more than a crawler. My last jeep in nh was built for crawling and climbing and I didn't get the satisfaction from that kind of jeepin.
If anyone has ever seen FOUR WHEELER mags "ugly jeep".. yea, that's what I want. That thing is awesome.
Gotta start another thread about steering boxes now...Til next time, y'all stay awesome and thanks a bunch!

 

[uberxj92]

We swapped a blown 304 for 318 with 360 heads and progressive 4bbl old cop motor. What a fun rude that was. MPG about the same as 304.

 

[carnuck]

First, you need a '72 up 360 or whatever AMC you plan to put in. The crank flange in '71 was different from later ones (made for Borg Warner automatics. The Chrysler/Chev cases with AMC pattern came after that)

pre-72 vs later crank flanges.

You can't bolt a 318 to an AMC pattern trans. You can swap the internals from a Jeep 727 to a Dodge 727 so you don't need adapter$ to bolt to a Mopar motor. (727 will NOT fit in a 9XX trans case however. Check the pan shapes match!)

On the AMC TH400 you can do the same. Put the internals into a Chev TH400 so it bolts to the QT tcase and then you need motor mounts for the (gag!) SBC.

My only "dislike" with AMC V8s is lack of fuel economy with a carb. That's why I'm selling the low mileage rebuilt 401 I have. I have a 304 that is getting 4.0L pistons so it can run on LPG. ($2 a gallon vs gasoline $3 to $4)

 

[hoobness]

First, you need a '72 up 360 or whatever AMC you plan to put in. The crank flange in '71 was different from later ones (made for Borg Warner automatics. The Chrysler/Chev cases with AMC pattern came after that)

pre-72 vs later crank flanges.

You can't bolt a 318 to an AMC pattern trans. You can swap the internals from a Jeep 727 to a Dodge 727 so you don't need adapter$ to bolt to a Mopar motor. (727 will NOT fit in a 9XX trans case however. Check the pan shapes match!)

On the AMC TH400 you can do the same. Put the internals into a Chev TH400 so it bolts to the QT tcase and then you need motor mounts for the (gag!) SBC.

My only "dislike" with AMC V8s is lack of fuel economy with a carb. That's why I'm selling the low mileage rebuilt 401 I have. I have a 304 that is getting 4.0L pistons so it can run on LPG. ($2 a gallon vs gasoline $3 to $4)

You and your temptations. Lol. . Noticed i m able to save some $ since the steering box i just pulled out isnt stock its the 76, the one I wanted ..allowing me to only need to replace a tie rod end and shaft coupler ..
...and you chime in with hey I got what you want for 750 lol.! The money just burns as soon as it hits the wallet.
Well see.. I need to get this thing rolling but I'll def keep the motor in mind if it turns out I bought a lemon, Although st Pete fl is quite a ways from Seattle.

But for real I appreciate the info on the swap to an automatic with the qt...
Thanks again