What are the correct intake manifold and head casting #ers for a 1966 360hp 396 block #3855961

Heads for either 325HP or 360HP in a Chevelle would be 3872702. The intake used with the Holley carburetor on both 325HP and 360HP was 3866948. The 3855962 4 bolt main block was also used on 360HP engines. The 3855961 block was used on both the 325HP and some 360HP engines.

I think their also the Q-jet intake ending also with ...948. I think that might have been pretty rare on 360 HP though...