Thanks for all the replies.
I was at the East Coast Indoor Nationals yesterday and talked to 383man and a couple of other folks about the engine, including a rep from a shop that does restorations.
The guy from the shop said he'd recommend a swap over a professional rebuild, given that it's a stock 318 and I'm just looking to be able to drive the car again. In fact, there's even a 78k-mile 318 sitting on a stand in their shop right now that came out of a customer's '68 Coronet (which is getting a stroker installed). The catch is that the compression is down on that engine, so it needs to be gone through anyway.
I don't know about the late-318 swap idea (the Fifth-Avenue scenario described above). An early LA 318 like mine is 230hp, those 1980s smog engines are like 130 or 140. Granted, a loaded M-body is probably pretty close to the weight of my '68 Fury convertible (hell, my '76 B-body was heavier than my '67 Fury, according to the MD MVA).
The more I think about dropping the pan and pulling main caps, the more I think "It's got over 204,000 miles on it, the bores are probably barrel-shaped, the bearings are probably shot and I know it's got at least one bad lifter (which collapses and then pumps back up--the noise comes and goes)."
And so I have this role reversal on my two toys: The '68 convertible, which has run whenever I've wanted to run it for 22 years, is a big paperweight, while the '67 4-door, which has had me chasing problems for most of the 10 years I've owned it, can suddenly be driven at will.
I'm gonna keep looking for engines and hope I can find one that's not too far away. I'll have to rent or borrow a truck to retrieve one, unless I find one with a really helpful seller.
Funny story: I was telling the owner of the comic shop I use about all this, and how there's a 318 in the Moparts classifieds right now that's cheap, but it's in Michigan. His reply? "Wait till I go to this convention in Novi, and I can load it in the (rental) truck when I come back." Nice offer, but a little nuts--also dependent on him selling enough at the con to make room for the engine.
