Smart things to check out on a 5.0 donor motor

[briancave]

I'm picking up a bargain priced 5.0 motor from a '98 explorer for my '72. I currently have a decent running stock carbed engine but want fi and a little more power so this is more of a winter project and not a big rush. I need headers anyway so the p-heads aren't a big deal for me. The engine has 120k on it and looks relatively clean but totally unknown history. The car was unfortunately not wrecked and looks like it sat for a while before being parted out so a dead motor is a possibility. The yard guy says they had it running but I'm not really buying that. Motor comes with a 30 day warranty. What would be the smart things to check out while I have it on a stand to make sure this motor isn't a total boat anchor without totally disassembling. Drop pan, check bearings and cylinders? What are clues for warped heads or valve problems? Any way of telling whether the engine was overheated short of obvious seizing? I'm OK with the idea of a rebuild but would like to know if I have a total loser from the get go. Thanks for any wisdom.
Brian

 

[EFI Guy]

Start with a leak-down test, it's easy to do on a stand and will tell you a bunch. It wouldn't hurt to pull the pan and peek at bearings either.

 

[briancave]

Thanks for that idea. I have a leak down tester. Wondering how using on a cold and not run in a while engine will affect readings.

 

[baddad457]

Check the condition of the freeze plugs. If they've shown any evidence of being pushed out, pull the intake and examine the vally walls of the block for cracks

 

[briancave]

Good thinking.
I hadn't thought of the freezing/block cracking scenario.