W2 Heads

I ran a set of 810 W2 with 2.08 intake valves just like those, ported with the DC porting templates back in the late 80's and 90's. If I remember right they flowed around 290 cfm intake and 200 cfm exhaust.
They had the small bolt pattern on the exhaust ports. But the Headman headers I ran with them came with a seperate flange that bolted to the small bolt pattern, and the headers bolted to the flange with 4 bolts on each outboard port and either 5 or 6 bolts (can't remember) for the 2 inboard ports.
The headers were A body 1 7/8 tubes with perfectly round ports and they were on a 69 Dart.