Yes, search for hypereagle's engine mounts. One thing about the AMC V8, in stock form, it isn't much of a performer. With an edelbrock aluminum intake and a healthier cam, and some headers, it can be more fun. If you're looking for easier V8-like power, buying a salvage XJ with a 4.o and swapping it and the fuel injection is probably better than swapping in a stock AMC V8.
There is a SX/4 for sale in my area with a stock 304 already swapped into it. I passed it up because it was poorly wired, and the rear axle was blown doing a burnout, so the seller had a Jeep TJ D35 cobbled under there for rolling stock. The car had too many needs for the asking price, so I didn't get it, and picked up the blue SX/4 I'm currently restoring. After I finish the blue car and sell it, I might consider the V8 car, if its still available by then.