Oh, easy. I was thinking about doing one of these setups myself.
Basically you have a early head, they have smaller valves and dont flow as much. They were designed for domed pistons. I'm guessing they would be equal to the same dish as a starion turbo piston which was 7:1. The chambers were something like 43cc roughly. The later engines that came with the newer style valve cover are made for a flat top piston and have something like a 75mm chamber. So bolting on that early head to the later engine gives tyou a high comp setup, but apparently the head flow leaves something to be desired.
They changed over heads somewhere around 1980 or 1981
Cool setup though. How does it run?
One thing thats weird, i dont remember the early heads having studs for the rocker assembly. THe first sure fire giveaway of a early head other than the valve cover is the huge pcv cutout in the front. later heads use a tiny half moon plug and run the pcv off the valve cover.
It came off a early imtsu truck, or dodge colt from the 70s, g52b or g54b
31 3000gt vr4
88 starion x2, 83 starion
88 cordia turbo
87 Montero swb turbo, 1987 Minicab van Supercharged
86 mighty max 4x4
84, 85, and 86 lancer ex1800 turbo
73 galant coupe
65 Debonair Deluxe