[77 TRASHCAN]

Originally Posted by J.C.you

"Nearly all" ....ok. Perhaps a misleading statement in his book.

If one had a 17 head with a 1.96 intake and then installed a 2.11 would the machining process of opening up the seat area alone increase the intake port volume?

Possibly.
The 17's were only used on 350's for 1968, (LOL, I believe).
The 11 castings that came on the 1970 350 currently in my car, necked down considerably beneath the intake valves. That area looked like a choke point to me in a bad way. I performed a bunch or grinding on them to open them up, similat to Jim hands book.
More of a choke point than the push rod area, that most consider to be a choke point in Pontiac heads. I believe that the 17's didn't seem as choked under the valves as the 11's....
Putting 2.11 valves in 11 or 17's would likely drastically change the intake volume.

The "D" port heads that I think about different than most are the monster chambered heads like the 7M5's and such that had the largest chambers. I wonder if those had smaller volume ports that 153 cc's?

Thanks for you perspective.
350 heads and engines are not widely modified or talked about much. I bought the 17's to possibly put on the 350 currently in my car to pump up the compression ratio, thinking that they were close to 72 or 75 cc chambers...