I saw a 7.3 in an early 90s lincoln towncar once, and there's that guy who crammed one in a mustang, so assuming lots of work, I bet you could get it done.

However, if I were thinking domestic diesel in big comfy domestic wagon, id probably do a 6.5 chevy turbo diesel in a caprice wagon. I figure that would be an easier swap, with a simpler lighter motor that isn't known for towing or strength really, so you aren't wasting the drivetrain in a wagon platform.

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