View Single Post
Old 02-22-2020, 12:47 PM
tgreese's Avatar
tgreese tgreese is offline
Join Date: May 29, 2003
Location: Medford MA USA
Posts: 11,225
Originally Posted by smittles
Thank you both for the input. Going back later isn't about the headache. Its about having a running vehicle that will still do a little towing and can be used for parts runs while I have the originals on work stands/bench. I might pick something different along the way, such as the 258 with 4.0 heads. That said, I'm not sure what the transition(s) were from the 230 to the 258. I know the frame was lengthened, but didn't it stay the same width? Should I be able to just replace the necessary crossmember(s) (if necessary) for the appropriate mounts? Right now I'm in a research and planning phase. I know it can be a hassle, but I really have had a bad year with cars. I was ready to put for sale signs on both the panels. Time prevailed, and I realize I could have a running project cheaper than buying an unbeknownst project. Thanks again. Y'all have a good weekend
If you want to swap, the AMC 232 or 258 or 4.0L will be as completely foreign to the Jeep as a Ford or a Chevy. There will be no advantage, in terms of swapability, to the AMC compared to say, a Chevy 250 cid inline 6.

Jeep went from the 230 to the early AMC 232 inline 6. This engine has a unique bell pattern and there is no family similarity with the 230. It's also different from the 258 which was introduced in 1970-71, which shares a bell pattern with the AMC V8s like the 304 and 360 and 401. The post-71 232 and 258 and 4.0L are drop in compatible with each other, but with neither the early 199/232 or 230.

In reality, the Chevy 250 will likely be the easiest swap, other than the flathead 226 I mentioned before. Adapters to the GM bell used by the 250 and lots of other GM engines are readily available new and on the used market if you look around. Nothing like the GM adapter exists for the AMC engines. The 250 is a good engine, comparable to the 258. You could also go Ford if you wanted - adapters also exist for most 20th century Fords to the T-90.

The frame length only changed for the CJ and Commando. Don't mix up those applications with the J-trucks and Wagoneers. Your engine compartment was designed for an inline 6, and most inline 6s fit without moving stuff around. V8s will interfere with the firewall unless you move the transmission forward. Not all sixes are the same length. The Ford 300 is longer, for example, and could be more hassle. You also should chose an engine with an oil pan sump to the rear, to avoid interference with the front axle.

Look at the used book sellers and get a copy of Petersen's "Engine Swapping Handbook." This was a large-format paperback that goes over the basic issues with swapping that you need to consider. And realize that swapping into a 4WD vehicle is more complicated than a passenger car, due to the transfer case, front driveshaft and front axle.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination ATs, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
ECO Green: '15 FCA Jeep Cherokee KL Trailhawk

Last edited by tgreese : 02-22-2020 at 01:07 PM.
Reply With Quote