360 swap

[surfbum]

I am kicking around the idea of replacing my tired AMC 258 i6 / 4.2l with a V8 sometime in the future. I have a line on two different 360's. One is a '73 and the other is a '78. Just wondering which would be the more desirable motor as the price is almost the same for both. I believe the 73 was from a truck(I assume a J10/20) and the 78 was just pulled from a FS Cherokee. They are both @ 500 bucks.
I also found another complete' 83 AMC 258 i6 / 4.2l for $100.00.
Looking for input on which avenue to pursue.
My jeep is a '79 with a AMC 258 i6 / 4.2l , T-18 /Dana 20 setup. Dana 30 front/AMC20 rear.
Thanks in advance

 

[Petescj]

Its gonna come down to how much money you wanna spend. You'll need a new fan shroud, motor mounts and radiator with the V-8. You'll also have to lengthen a few wires with the correct gauge. Obviously its gonna depend on how complete the V-8 is , i.e. brackets , dizzy and such. Its not a difficult swap though and you got a Transmission that's plenty capable already in your T-18 .

Brand new mounts , fan shroud and radiator will run you about $350. then the extra $400 for the motor. I have a 360 in my CJ5 and love it. Im not sure if your clutch is compatible but I think it is. Im at work and cant search.

 

[CJ]

Don't for get the flywheel if it is a manual 360. The throttle cable is different and you'll need various hoses as well as new exhaust and possible an ignition system. As Pete said - it is all bolt on and relatively easy.

 

[surfbum]

Thanks Pete. I was wondering about the clutch. If you have time and could find out, I would greatly appreciate it. I know the flywheels aren't interchangeable(one's internally balanced and one externally, but not sure which is which). All 3 motors are complete from carb to oil pan and include all the belt driven accessories and exhaust manifolds. Also was wondering whether the Transmission /tf case will move, necessating longer/shorter driveshafts. How about the box mounted behind my wheelwell (I'm guessing it's related to the ignition sys). I that compatible? ....can you tell I'm a GM man...lol.

 

[surfbum]

Thank you also CJ. Good point, I'll have to check and see if the 360's included the flywheel. Are the V8 AMC's the ones that are externally balanced??? If so, not having the original flywheel would be bad. I guess I would have to check and see if the exhaust manifolds would be different for a CJ than for the fs truck/cherokee too. Is one year 360 better than the other? (1973 or '78)

 

[CJ]

I show only one flywheel for the 360 from 71 to 73 -->> http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=FLYcatalogAMC and only one from 74 to 79. But I would definitely call them as it is very confusing.

As for manifolds, if your going to have an exhaust built at a shop - I don't see where that would matter.

The 360 would be the same dimensionally but the 73 has more HP and torque. -->> AMC V8 engine - Wikipedia, the free encyclopedia 175-220 from 71-75 VS 160 from 78-81. I would also consider mileage.

 

[Petescj]

Ok got the clutch info for you and I know this works firsthand. I had a AMC 304 in mine and switched to a 360. I used my new clutch from the AMC 304 . The AMC 258 i6 / 4.2l and AMC 304 for 76 to 79 use the same part # so your good. What were your plans for exhaust? Mine was pretty easy since pacesetter had a complete system headers to tailpipe. Ive only seen them for a CJ5 not a CJ7 though.


Clutch Kit and Other Jeep Parts and Jeep Accessories by 4 Wheel Drive Hardware

 

[surfbum]

Thanks for that clutch info Pete
As far as the exhaust.... I was planning on installing a set of headers and then having a set of duals bent at the local shop. What year did they start putting CAT's on Jeeps?? Sure would like to ditch that/them.
I haven't gotten to look at the 360's yet, but as far as the ignition is concerned; would the '73 be a points dist? I believe the '78 uses a system like the Ford Duraspark... or am I wrong here? I will be partially tearing down the motor to check it out, but want to avoid changing the dist if can. Hopefully when I plastigage the bearings, they look good and I can leave the rotating assembly intact. Just freshen up the top end and replace the cam, timing chain, waterpump, oil pump, and clean the heads up.

 

[Petescj]

If the exhaust manifolds are intact and in good shape Id skip the headers if your looking to save a little. Headers are more for top end and the benefits in a Jeep are marginal. I think the 73s were points and your correct about the 78 using the motorcraft set up. I used the stock ignition on my 78 and it was fine.

I don't know about Jersey but Pa. has emissions and I had to get two small cats from Summit Racing added into my exhaust. Their basically there for show.

Thanks for that clutch info Pete
As far as the exhaust.... I was planning on installing a set of headers and then having a set of duals bent at the local shop. What year did they start putting CAT's on Jeeps?? Sure would like to ditch that/them.
I haven't gotten to look at the 360's yet, but as far as the ignition is concerned; would the '73 be a points dist? I believe the '78 uses a system like the Ford Duraspark... or am I wrong here? I will be partially tearing down the motor to check it out, but want to avoid changing the dist if can. Hopefully when I plastigage the bearings, they look good and I can leave the rotating assembly intact. Just freshen up the top end and replace the cam, timing chain, waterpump, oil pump, and clean the heads up.