That will be a good engine for your truck. It is a good that it came with Oval Port heads, as opposed to Square Port, because it will give you good low-end torque, which is want you want in a truck. If you put flat top pistons in that engine, then my guess is the compression will be about 10.5 to 1, which is a little high for the street, but do-able. Make sure the heads valves are modern "hardened for unleaded gas" type valves, since it came out of such an old car.
I looked up your casting numbers, and this is what you have.
Block : 3963512....454.......70-76...2 or 4 bolt
Heads: 3872702....65-66...oval..CLOSED..396, 427, 98cc chamber
I am not sure if these heads will bolt up to a 454. Does anybody else know? You may also need hardened valve seats for an old set of heads like yours.