by Ferrous_Head » Thu Sep 12, 2019 4:42 pm
I've had several sets of the heads with the "x'. couldn't see any major differences but ...
I think they made changes to the ports in 69. After the race department spent a lot of time looking at port velocities and flow I suspect the results were incorporated into the stock heads. This would have required new cores. But I have no way of verifying that.
"I know only too well the evil that I propose, but my inclinations get the better of me."