3988920 heads
 

Just got a set of the 920 heads that have been machined for the 2.02/ 1.60 valves and screw in studs and big springs, they look good except the combustion chambers look a little big. Was wondering if any one can tell me a little about them, and i have also located a set of 492 angle plug heads would like to hear some comments on them as well

They`re typical smog heads released in the early 70`s. They have the large 76cc chamber to low compression to meet smog requirements.
They aren`t peformance heads and really weren`t worth investing big valves into. All the old chevy heads such as the camel backs few bother to run anymore when you can get a set of Vortec heads and be 30 horses over any of the other factory heads is why.