Well, here's the short version of the update. I blew the motor up!

Slightly longer version...

I found a good condition used 4.9 for $100 so decided to just get that. It was 65 miles away, so I had some concern about a 130-mile trip, but I've put about 600 miles on this thing since I bought it, so I figured it would be fine. And it was totally fine for the for the first 60 miles, and then it rapidly overheated - we're talking mid-range to red in a mile.

I'll spare all the details, but I managed to get to the seller's house and get the "new" motor in the truck, but it was clear I wasn't driving this thing home. Truck was flat-bedded home with a motor in the bed.

It's certainly got a cracked head and/or a blown head gasket. I suppose I may take it apart one day and see what I see, but for now, that's not a priority.

Here's my new priority.... https://www.ford-trucks.com/forums/1...l#post11840695

Thanks for the help in this thread - it's certainly been educational, so not at all a wasted effort.

 

Got around to pulling the head on the old motor the other day. The problem was easy enough to determine - broken head bolt right about in the middle of the engine on the driver side. A quick inspection didn't show any head cracks, so I'll hang onto the head as a spare and probably scrap the short-block. Might remove the crankshaft to use as a mailbox post.