Big block and head ID needed

[navy2kcoupe]

My neighbor just got a 396 engine and was wondering what it came out of. The block casting number is 3855961, with a "C1" also cast in at the rear of the engine. The pad at the front is stamped TOII4EF F116518. The one head I was able to look at is a 3872702 head With D-5-6 cast into it, and BOTH heads have 0836 stamped on them. He is planning on putting it into his 72 Chevelle and was curious where this engine started out. The block also has PASS cast into the rear, as does the one head I was able to see. Anyone want to give me a hand ID-ing this engine?
Thanks.......
Andy

 

[Vettehead Mikey]

'66 Chevelle 4 speed S/N 16518 , nice find.

 

[paz72vette]

The head is 1966, closed chamber, 325, 360 HP, L-34/L-35/L-36, 98.4cc
Oval port, 2.06 intake, 1.72 exhaust.

Cheers

Vito