looking to find specs on 340-X heads.
They have 2.02 int valves and 1.60 exh valves. They were used only on a 340 from 68-71. Chambers usually cc out at approx. 72 cc's in stock form. I have a set and flowed them in basically stock form. The only diff from stock was they had a good multi angle valve job and stainless REV valves. Here's the numbers
Lift----Int.----Exh
.100----60-----50
.200---120----104
.300---173----131
.400---210----143
.500---220----146
.600---215----148
They were milled .010 and with the stainless valves cc'd 66 cc's.
I think the REV valve design took up a little more space so that's why they cc'd so low.