Motor ID

[Turtleman]

I seem to run into more stumps than I can mange..
I really need to find out what motor is in this truck,, I knows its a 350 short block but cant find out what year or what it came out of.
The stamp on the casing behind the right side head is 3970010... or at least that's the best I can see of it,, its so tight in there I have a hard time accessing that to see.. I see no other cast numbers.
I've been trying to convert to disk brakes and power steering but I cant quite get the correct Power Steering unit or mount brackets to fit on the motor.