AMC engine swap?

Don't tell the AMC guys you want to drop a Mopar in. Sort of like suggesting a SBC in an A body.

The AMC V8 is a pretty good unit and aftermarket support is strong. You can buy what you need to make this swap as opposed to the Mopar swap which will require everything to be fabricated. Motor mounts are just the start. You are on your own with linkages, plumbing and electrical. Still, it can be done.

Another option is the 4.0 six out of the later Cherokee and Wagoneer. It was developed from the original AMC six and will bolt in place. It can be stroked with a crank from a 258 and it's a pretty stout performer. Lots of info on this on the AMC sites and you could make the case that it would be a Mopar swap. Just don't say that to the AMC guys!