Marlin;
These heads started off as 1.94/1.50 units, I had them opened up to 2.02/1.60 valves and had the hardened seats installed. The factory 2.02 heads have the chamber relief around the intake valve, but I personally feel this modification is unnecessary. Some claim that you lose flow if you don't relieve the chamber when going to 2.02 valves, but I feel the real area of importance when going to the bigger valves is relieving the valve bowl. (You'd be surprised how many machine shops skip that step when cutting heads for bigger valves) I prefer to leave the chamber alone to keep it as small as possible for the sake of compression.
These heads are set up essentially the same way as the heads on the crossram 302 engine on my website, and it made an honest (and easy) 377 horsepower, so I don't think they're giving up too much flow.
Eric