'72Blu....that is what I was looking for. I already have a Performer RPM knock-off intake, not on the engine at this time, and wondered if the port window was equil. Time to save up my pennies for a set of Engine Quest heads......
Bob
This is correct. The 308 heads are the same swirl port design as the 302's, but have the larger 360 sized ports. HOWEVER- they are open chamber heads, not closed chamber like the 302's. The set of 308's I had ported for my 340 flow 264 cfm on the intake side at .500", so they're pretty capable heads, pretty much similar to any of the J or X heads with the proper sized valves, just a better exhaust port. The set of 308's I have actually cc'd out to be 65cc's before I had them cleaned up, they ended up at 64cc's. But like the X and J heads I've heard they can run much larger also, I must have gotten lucky.