I'm going to pick this truck up for $100 on Friday. Guy doesn't know much about it. From what I can tell it's a newer style FE with propane? Notice anything else? It's going to be a parts truck for other projects.

 

The propane system may be valuable to an offroader with a carb whose engine dies at extreme angles.

I recall reading something about 'mirror" blocks... where the numbers are cast in reverse like yer pic.

 

What's with the dual fan belts?

 

If it's run on propane it's entire life, I would expect the engine to be extremely clean with no sludge or deposits when you tear it down.
As a motor fuel, propane is much better than gasoline. There should also be minimal cylinder wear. Propane is a dry gas as opposed to "wet" gasoline. There's no liquid fuel to wash the oil off the cylinder walls.
There's also no sulfur in propane so oil doesn't turn black.
Not to mention the higher octane rating.

 

Mirror 105 blocks are a little more desirable because they usually have somewhat thicker cylinders and webbing for the mains. They aren't that rare or anything but I think were toward the end of the FE production, most just say 352. I used one for my 445 build and had no worries boring it unlike some of the FE blocks.

 

With the belt setup that it has, It might be out of a larger truck like a f600.

 

Thanks for the info everyone. He thinks it's a 390, but I'm buying it regardless. Intention was to turn my 360 into a 390 with this crank and rods, but I think I'll just use this motor instead.

 

Has the optional dual belt drive alternator, available on all 1965/76 F100/350's with I-6 & FE engines.

Here's a pic from the parts catalog showing 1974 360 & 390 fan belts for dual belt drive alternators.

 

It has a 390 code VIN. Interestingly, there are a set of heads in the bed (along with two batteries I can turn in for $) so there is a chance they upgraded the heads for the propane. Time will tell! Its had propane since I was -1.

 

Actually not a bad looking truck.
F25MRB53439
F25=F250 2WD pickup
M=390 4bbl V8
R=San Jose assy. plant
B53439=1976 model year sequential serial number

 

Man that's a Lew price, Lew being that guy that magically finds all the best deals on trucks an parts. Hell, my CL has piles of rust for 100 bucks

 

Yes, that is a 501 "mirror" FE block. Other FEs will have DIF. Just different foundries It is supposed to have slightly stronger webbing on the bottom end. I have one of these in my queue all cleaned up and ready to assemble. I see a little more material down there but it doesn't seem to be that big a difference.

 

Almost looks too nice to dismantle, unless there's no title or something.