Advice on buying junkyard engines?

I've never bought a junkyard engine before. I actually need two engines, a 5.9L Magnum that will go in my '71 Dart, and a 4.2L V6 for a '97 Ford F-150 that blew up. While I expect to do a little freshening up on one, I don't want to need to do a full valve job, new rings and bearings, line boring the crank or cam bearings, etc. The goal is not to buy a $600 engine so I can sink $4000 more into it.

i think that you may need to adjust your expectations a little. while i understand not wanting to get into machine work, gaskets, rings and bearings should be a possible foregone conclusion. and also, that's not a ton of dough to drop.

e-bay has a lot of resellers that offer complete motors with warranty, generally they'll list mileage which can kind of, sort of give you an idea of what you're getting. and if you're not in the "roll around in the muck and pull it yourself" category that's a viable, yet pricey option. but likely to get you on the road the quickest and least painful way.

another option would be to buy a complete vehicle that's running and just pull the motor and scrap the rest.

find a specialist breaker near you and they'll likely have the best parts at the best deal.