318 gurus/historians

Someone tell me what I have. I bought a '77 D100, neat little truck, I've had many. It had sat for 18 years in a metal shed. 318 auto with air, P/S, P/B and the adventurer package. I slowly brought it back to life, and it ran great. Having sat for so long, it started leaking oil, trans fluid and even gear oil from the rear end. Got the trans and rear taken care of, so all that was left was the motor, out it came! After pulling it and washing it I started noticing traces of orange paint under what was left of the mopar blue. I had noticed the the casting date was 1981. As I disassembled things, I started noticing the following: the intake had been removed before (silicone on the china walls), double roller timing chain (cheap one I've never seen before) and a 90* oil filter adapter. Didn't really think much about it until I started to paint and reassemble things. I set the new felpro intake gaskets on the heads (I always use the 360 intake gaskets) they matched. I looked up the casting numbers for the heads and they said '80-'81 318 hipo, 360 heads. I cleaned and painted the harmonic balancer and it has 30*before and 30* after TDC (never ever saw that before). I know it's still a low compression 318 with 360 heads. But, just curious, truck motor or cop car motor. What do you think?