I looked them up on mortec and it only said 76cc head. Before I pull the heads or look at buyng aftermarket, what size valves are these fitted with? Also do they have hardened valve seats or are they too old of a style? casting #333882.

 

should be hardened seats, 1.5 on exhaust and 1.94 intakes, but you ought to double check me, i've been wrong one other time and SBC parts

 

The 882 casting came with both 1.94, 1.5 and 2.02 1.6 at different times. With the 76cc chambers it's probably the 1.94's but the only way to know for sure is to call 'em up and ask.