074 Heads

[m22mike]

I have a nice set of 3946074 heads dated 11/30/73. So I guess that makes them parts counter items ?
Was curious to what these are going for should I want to sell them or list them on Ebay ?
There is what looks to be a repair to plug a hole.
Look at the picture below, there is a small stud or bolt ground flush, with a washer around it,and there is some silicon around the washer, any ideas why there was a hole here ?. On both heads in the same place.







Also both heads stamped "EVERHART" on the ends. Is this just someones way of ID'ing the heads ? Or was this a race team ?







The stud holes for what I understand to be for a ZL1 application have been pluged.




Thanks for any insight, Mike