So the Eagle is technically a materially different car, and not "just" a lifted Concord/Spirit. Thanks, Wikipedia and the internet in general are useless for that kind of information anymore. (Explanation: I'm still planning on becoming a modder at some point, and part of what I'm doing involves making a rather long list of cars to select randomly from at a later point. I had the AMC Gremlin/Spirit 70-83 and AMC Hornet/Concord 70-83 on the list separately at one point, but then I realized that the Eagle had Spirit-based short-wheelbase bodystyles, meaning that if the Eagle shared enough with its 2WD cousins, it would tie them all together to make an "AMC compacts 70-88" entry. But from what you're saying, it sounds like the Eagle's chassis is just different enough to not count.)
It's more a matter of, I wouldn't really want to. The Eagle, while it did see some legitimate rally use, is very slow stock and doesn't have a lot of aftermarket support that I know of, certainly not anymore. The Gremlin is the star of the show to me; at least it has the gimmick of being able to spec a factory V8 (and fit a much larger one) in a pretty light car. In fact I'll probably take the Hornet/Concord off my list to slim it down a little. In my mind, a different floorpan combined with a different nameplate makes it a completely different car, enough to have (in BeamNG) a completely different heading in the menu. The reason I asked is because the Eagle uses both SWB/Gremlin and LWB/Hornet bodies, so if the bodies and chassis were the same then it wouldn't have made sense to separate the 2WD models from the 4WD ones and each other. But from what you're saying, it sounds like the Eagle used materially different unibodies from its 2WD cousins, which is the question I was trying to answer. Not that it's likely to matter anyway, the list already has over 110 cars on it, many of which I'll probably struggle to find accurate information on. (If you know where to find structural blueprints, accurate chassis rigidity figures, and engine details on prototype racers and old concept cars, that would help.)
Well I have a ton of old factory brochures and a few service manuals and stuff but most of it is for Eagles and Jeeps. Although I have some post '78 Concord and Spirit brochures too I haven't really looked into blueprints and stuff like that