Sorry, this question probably gets asked to death, but...
My son gave me a 76 F150 4X4 long bed, 4 speed, and what I assume is a carbureted 300.
I looked on the side of the block just above and ahead of the starter, and found 3TE G015 AA, perhaps 3TE 6015 AA. For what it's worth, the crank pulley has three grooves, two around the alternator, and one around the Saginaw power steering pump in factory Ford bracket. The cab is set up with air conditioning, but the pump, hoses, and everything on the motor is gone.
I do not believe this motor is original to this truck. Any ideas of vintage, and if I've assumed the displacement is correct? Thanks!

 

The number is most likely 6015, not G015 as thats the basic part number for an engine block. Is there a letter in front of the '3TE"? If so, it could give you an idea of the age of the engine. "D" is '70s, "E" = '80s, "F" = '90s. If the casting number doesn't have a letter, then its most likely a 1973 DESIGN 300 (I have a '78 block with a '5TE-6015-AA' casting # on it). The reason I say design is that the casting number on the block (& head for that matter) is the date when the design was first cast, not when the part was actually made. Ford had/has (?) an 'empty-bin' policy in that they'll use up older parts as long as they're usable in newer vehicles. (I always laugh when someone sells a "numbers matching" old ford...) So, its entirely possible that the engine is original. If its not, it shouldn't be too much of a problem. Many of the casting number changes deal with cast-on mounting points & probably won't effect much unless you're adding more accesories than a luxury car...

If you're still a little unsure if you actually have a 300, measure the stroke. Pull out one of the spark plugs, put a thin rod down the hole, turn the engine over (by hand!) & measure the distance the rod travels. Aproximately 3" stroke is a 240, 4" is a 300. I will say that if it turns out to be a 240, then its not the original engine as the 240 was discontinued in '74.

I hope this helps.
Edwin

 

There's nothing in front of the '3TE'.

The big reason I'm wondering about this engine is that the paint is flaking, and there are at least three different colors, blue, yellow, some black, and someone tried to paint the valve and side covers a funky metallic silver. I see no evidence of overspray anywhere in the engine compartment or frame rails.
Two weeks ago, we demolished the basement in preparation for remodeling. We filled the bed of this truck up with sheetrock and lumber, and it's all it would do to keep running the three miles out and back to the dump.
Last week, I rebuilt the carburetor, as about a month ago, I installed new plugs, wires, points, cleaned the cap, and timed it. Still wouldn't stay running. I pulled the plugs, and they didn't look too terrible, so I cleaned them up and reinstalled. THEN, I pulled the 'cleaned' distributor cap...heavy carbon tracks between three adjacent contacts, and between the center, so it was trying to fire perhaps up to four plugs at once!
New cap and coil, and fired the thing, and MAN O MAN!!!! You ain't never seen anything so fixed in all your life! BUT...accelerates slowly, and top speed with a load is about 50 mph, unladen, perhaps 60. I'm certain that this thing is really, really tired, so this weekend, I'll have to pick up a vacuum gauge and a good compression gauge, pull the side and valve covers and see what is left of it. There is NO smoke out of it, even running nasty, I see no evidence of oil consumption or leakage. Just no guts.
Thanks for your help!