c90E head/valve ?

I recently got a set of 351w heads stamped C90E. What is the chamber size on thes? They are the machine shop getting 1.6 exhaust valves installed and was wondering if later on I decide to machine the heads for screw in studs and then use a roller rocker will I still be able to use the valves that have the longer tip on them or will I have to switch over to a chevy or late model ford valve?

I'm planning on using a b303 cam (its a roller 351) 224 dur and .480 lift would the stock 69 springs hold up or will I have toget different springs? Or could I swap a set of springs off of my 40p heads I have and use those on the 69 heads?

Thanks to all that reply.

Thanks. The springs from the p heads have about 2k miles on them, so they should be good until I get the dough to machine the heads for screw studs and double valve springs.