View Full Version : amc 232 & 258 parts interchange

04-19-2004, 02:46 PM
I was just wondering if anyone knows what parts if any are interchangable between the amc 232 & 258. Also if the IH models are a 100% interchangable with there jeep counter parts? For example will jeep heads and blocks interchange with IH heads and blocks or are the bolt patterns different?

04-19-2004, 02:48 PM
By bolt patterns I mean bellhousing to block and head.

04-19-2004, 02:50 PM
not sure about the parts being different or the same, but I have a 258 that I tried to sell once, there was a guy that had a postal Jeep W/ a blown 258 so he wanted to buy mine, well I took it to him and they were different so of course he backed on the deal. To answer you question are the 258 for a Jeep and a Scout the same?? maybe some, but no not all.

04-19-2004, 04:47 PM
all the postals i've ever seen were 232s. maybe that's why they were different. the jeep and scout engines were both built by amc. same motors. my 232 is different than a 258. i don't recall specifics now, but the heads are different and a few other odds and ends. the differences start at the bellhousing/ clutch. i figured i was good to go having a jeep engine, just use a jeep clutch. not! jeep motor, IH trans. if you are looking at either one, i'd lean towards the 258 for the available mods(tons!). if you want bone stock and a strong motor the 232 is fine. mine works for me and how i use it, but i was dissapointed there were so few options as far as add-ons.

04-19-2004, 04:55 PM
to the best of my knowledge, the number one concern is the location of the starter. (drivers side or passenger side.......which also indicates small bellhousing/early/driverside starter versus large or same as v8amc/late/passenger side starter. bobn

04-19-2004, 04:58 PM
here's a link to some info on amc sixes.
this is off jim weeds site i linked to off of offroad.com:
The AMC-built 232 (1971) and 258 (1972-1980) were factory options but not very impressive, no fish nor meat. IH-fans consider them not very desirable as they usually last only 100.000 miles between rebuilts which is not much compared to the 200.000+ miles the IH engines were designed for.

Performance parts are readily available as the engine is identical to those used in CJ's with the exception of carbs: AMC used Carters and IH used Holleys. From my docs I learned that AMC's sixes drop easily into all Scout II's. Never saw this done but this would mean you could swap in an AMC 304 or 401 also, maybe with another motor mount. The AMC V-8's offer much higher power at less weight.
the amc V8s swap in place of the six, not in place of an IH V8.

04-19-2004, 05:15 PM
The IH 232 and AMC 232 are the same beast. As is the IH/AMC 258. The 258's are basically stroked 232's with the starter mounted on the passenger side of the block instead of the driver's side. The big differences occur when mating the sixes with the IH and AMC trannies. Bellhousing lengths and bolt patterns are different, as well as input shaft lengths and thicknesses. The trannies mated behind Scouts and Scout II's with AMC sixes had a rather long input shaft, about 10.250", which is the same length as the V8 models. Heep shafts were generally shorter, and in fact not many components behind the flywheel are compatible with IH. Also, in 1972 AMC changed the bellhousing bolt pattern on the sixes to match the ones on the new AMC V8's (304/360, etc.) So post '72 AMC sixes are not a direct bolt-in on earlier set-ups.
Hope this helps rather than increases your confusion. I own a '70 800A w/ the AMC 232 and I like the power and economy I get from it. But as far as performance (aftermarket) additions go, there's not much out there.

04-19-2004, 06:03 PM
This is all helpfull, also does anyone know if intake and exhaust manifolds will interchange between the 232 and 258?

04-19-2004, 06:17 PM
I'm not exactly sure why they're not, I just know they're not. I got my exhaust manifold off a Gremlin, and my intake is a four-barrel manifold from Offenhauser. The four-barrel universal Carter I have works great with the six, which always seemed to be starving the first two cylinders with the OEM Holley single-barrel carb. I actually get better mileage with the four-barrel (15-18 mpg). Of course, I also installed an electronic ignition, which doesn't hurt your mileage either. :D

Geoff B
04-19-2004, 06:34 PM
This is all helpfull, also does anyone know if intake and exhaust manifolds will interchange between the 232 and 258?
I'm running an '82 Jeep 2 barrel water heated intake off of a 258 on my '71 232, as well as headers intended for a 258. To add to what Old Goat said, the AMC sixes were sized in 199, 232, and 258 displacement. 1972 was a pivotal year for the sixes, they changed the bellhousing pattern (marked by a change in starter location), raised the deck height of the block to accomodate the 258 stroke, dropped the 199 altogether, and changed to stud mounted rockers instead of shaft mounted, although they went back and forth a couple years on that last point. Also the oiling system passages were changed through the block as well to accomodate the change in valvetrain. So you've got to be pretty careful when swapping certain engine hard parts, but I think manifolds are pretty safe, other than the change from exhaust heated to water heated intakes in 1980.

04-19-2004, 07:54 PM
geoff, you're the first person i've known of to swap on the newer manifolds. i was always under the impression they wouldn't work. maybe the deal is you have to do both because of the exhaust heated intake? either way, that's good news for the swap meet scavenging. one other note, someone had posted on an amc site that you can grab a rambler intake as they used 2 barrels on em. then i just need the header...........

Geoff B
04-20-2004, 08:38 AM
There are 2 barrel versions of the old cast iron exhaust heated intakes that would bolt on as you said. The old (pre 1980) and new manifold are different in height where the bolts clamp on the manifolds, the newer manifolds use shorter bolts. In my case, I put the headers on to replace a cracked exhaust manifold with the original 1 barrel intake, but had problems with cold weather performance because the manifold was no longer heated. The aluminum 2 barrel is water heated and solved the problem, and as a bonus i use a 2 barrel motorcraft carb which runs excellent, worlds better than the factory 1 barrel. So you can use the late model aluminum 2 barrel intake if you also use the exhaust manifold from the same year, or do headers as I have. The headers, by the way are Dynomax blackjack dual outlet headers intended for a CJ, and were a pain to fit on my 232 with the drivers side starter. For clearance, I had to ditch the IH starter, use a ford starter (no solenoid) and drill and machine the housing a bit for the IH starter bolt pattern. I sounds redneck, but it came out nice, the starters been in there for 5 years now. I also had to dent one of the tubes a bit for front axle clearance ( a SOA would not have that problem). Photos of my swap are here:
I'm very pleased, but probably wouldn't do the headers again, go with a late model exhaust manifold instead.

04-20-2004, 08:45 AM
nice scout! i really like the tire/jerry can carrier. think the driver might get pulled over to check I.D. as she looks a little young. don't know i'd want to mess with the starter and wonder if the single outlet would be as bad for clearance or worse. at least you found a way around it.

04-20-2004, 08:51 AM
Sounds like a tight fit, Geoff. What kind of performance increase have you noticed with the headers? I wonder if a smaller "Mean Green" starter would work in that situation. BTW, nice truck!

Geoff B
04-20-2004, 09:08 AM
The power difference with the headers was, I suppose, slightly noticeable, but a lot was probably in my head just because it sounded better, looked cool, etc. I noticed a big difference in power and mileage with both the electronic ignition and the motorcraft carb with the intake. The ignition was good for 2-3 mpg and made the distributor pretty much oblivious to water crossings, and the carb and intake made a huge difference in accelerating onto the freeway and highway running, and off road performance has been awesome. Like I said, I probably wouldn't do the headers again, but I'm happy with them since I did. Thanks for the compliments y'all, I'm pretty proud of the old girl, put a lot of busted knuckles into her.