Which has little to do with anything when the rule stipulates the heads have to run a 1.50 exhaust valve.
You have two choices, put seats in the bigger heads so you can make them fit the rules....... or run the small heads that come with the 1.50 valves.........and give up the 40hp that comes from using the bigger heads.
I went with putting seats in the bigger heads so they could use the 1.50 exhaust valve.