cleedustee

I recently bought me a 1972 f100 stepside. The VIN tag says it came with a 390ci motor. The guy I got it from says he thinks it's a 351ci and with all the research I've done trying to identify this thing, I'm pretty sure it's a 351c. But here's the thing... The block stamp is "D1AE". How could it be a '71 351 if the 351 didn't come out till '73 or whatever??? I'm very confused. What's another way to identify this motor so I can get parts?? Please help.

hangmans8

390 the valve cover bolts to the intake manifold. Thermostat is on the intake.
351 had a completely flat steel timing cover. Thermostat is on the block.

Blacktip

It could be a 352. Same engine family as the 390 and very common years ago - if the 390 was replaced at some point, that might be what you have.