I agree with Dave.Follow this logic.You build up a stroker engine,cam it up,and then on their best ported day OEM heads choke it because you can't open the heads up enough to feed the engine.There are very good reasons for the aftermarket heads and if you could come even close to them with a stock head,there wouldn't be a market for the aftermarket ones.A rule of thumb is .5 X the c.i= the intake cc size.There is no way in the "stock" OEM heads your going to open them up to 195CC's.I also agree the use of roller rockers for the street is a waste of time and money in most cases.So you did your build for a stroker and now you need to finish it with a decent cam and head combo.