It's just my opinion, but if I had a dollar for every time a "this engine was just rebuilt xx miles ago" engine turned out to be utter rubbish, I'd be a rich man. 

 IF they have documentation that the engine was rebuilt by a reputable rebuilder (I can count those on one hand.....well maybe three fingers), prefereably a factory type operation, then you might be able to have some confidence in the engine.  But in general, a "just rebuilt" engine is an unproven and unknown quantity. 

An engine in a sedan that's running well and has been doing so for 100k or so is ideal to me.  If it's got maintenance records and has been even marginally well cared for, I know that factory-built engine's got 400k in it, of which only 1/4 of it's life is gone.  If an engine was put together by heaven knows who, using who knows how much care or proper triaining and tools, well, you have no basis to say whether you can expect 300k or 30k out of that engine.  I've been through the factory workshop manuals for rebuilding these engines.  It ain't no smallblock chevy.  I'd take a high mileage runner that I could test drive first over some promise of "just rebuilt" any day of the week......hey wait a minute.....that's what I DID!  

 And then of course there are the questions of WHICH engine to get.  To me, a 617A of '82-'83 vintage is the best one to get.  They have higher lift cams than the '79 vintage, no trap oxidizer, iron head, a real bullet proof setup.  The only advantage to the earlier motor is no EGR, but you can either get early manifolds to swap onto your later motor, or else just use blanking plates to block off the EGR ports on the later manifolds to remove it.  (I know dealership mechanics who were instructed to insert a brass pin into the EGR vacuum tube on new cars to prevent the EGR from ever working in order to avoid driveability complaints and carbonizing warranty claims - you don't want EGR on these engines).  Anyhoo, that's my opinion.  Worth just what you paid for it!

 -Dave G.

For moving the forum that is.  I couldn't believe what I saw when I went and looked at the thread that Kashi posted a link to.  It's been a while since I posted on BWF, but last time I was there they didn't have those gratuitous add links grafted onto every friggin' post.  What a PITA!  Can you imagine a link to some internet Ford dealer popping up every time you typed the word truck?  Yeesh....

-Dave G.