Don't know if it is from a truck or not but it is a 1979.
Here is somemore info about your 1979 engine.
The day of the event 35 blocks were put to the test. The big block Ford had a production life from 1968 till 1996 and it was used in nearly all Ford fullsize cars and trucks during that time. Block castings from every era were present, C8VE-A,C9VE-A,DOVE-A,D1VE-A2A, D1VE-A2B, and D9TE blocks were tested. There were several Cobra Jet and Super Cobra Jet blocks with four bolt main caps and even one Boss 429 block in the mix. Blocks bearing marks from these 3 foundrys were all present at the block summit. The foundry marking is on the block at the top rear near the
oil pressure tap boss. The marking that looks like CCP is the Cleveland Foundry, DIF is the Dearborn Foundry and finally MCC is Michigan otherwise known as the Flatrock Foundry. From what could be determined from the block summit data what that blocks were originally cast at Dearborn Iron Foundry at least until the D1VE and later castings when production was moved to Flatrock. Blocks were produced at Flatrock until the introduction of the D9TE block for 1979 when production was moved to Cleveland Cast Products till the end of production. What is interesting is how each foundry used unique tooling to produce the blocks each of which having unique and often special features. For instance, the DOVE-A blocks produced in the Dearborn foundry are the only ones cast with extra thick main webbing to allow for the factory instalation of 4 bolt main caps. Not all of the DOVE-A blocks have 4 bolt mains but they all have the provision for them. The D9TE blocks are cast with a cylinder wall that's .250 longer than other production blocks and this is an interesting feature. It's not known why the factory changed this but it is certainly a plus if long strokes are being run, giving the piston more support at BDC. (4.500 stroke 6.700 rod combinations work fine in all production blocks) SVO blocks also have this feature. Not to be left out, the D1VE blocks from the Michigan/Flatrock foundry are the most numerous and they were used in 429 and 460 production from about 1971till 1978.
Other production block features are: C8VE,C9VE and DOVE blocks all have a narrow pan rail. D1VE blocks can have a narrow pan rail but only in the AA version. AB or A2B blocks have a wider or unreleaved pan rail as do all D9TE blocks. Some DOVE-A blocks are cast with a large "A" on a square boss at the front of the block. Many of those particular blocks are also cast using Boss 429 bulkheads front and rear. This bulkhead has slightly more material under the front main cap than the regular bulkhead. Not all "Boss 9 bulkhead" DOVE-A's have the large "A". The rear bulkhead appears to be identical to other blocks with the exception of additional bosses near the rear cam bearing bore. In the actual Boss 429 block this additional material was used to accomidate the Boss 429's unique oiling system and also a bolt on cover instead of a drive in plug for the rear of the camshaft. None of the DOVE-A blocks are tapped or machined any different than regular production blocks in this area.