GS Head - Larger valves?

[V8Pinto]

A few people have mentioned installing larger valves in the GS head, can anyone fill me in on what size they are?  I'm looking at valve seat cutters (for car heads) and want to see if I can get the right tools for the GS head in the same purchase.

Thx

[Lars]

I'm not 100% sure, but I think intake was 39 mm and exhaust 37 mm.

http://www.hobbytechnik.de/suzi/cont2.htm

At that page on the right side - bottom, you can see the cylinder head with the valves.  (the picture is clickable) I think the seats can't be cut any bigger because there's no space in the head left. The only way to get more flow is to use an 8 valve head.