i dont have the heads yet i ordered them last week they say up to 5 weeks.the reason for all of this is that my 195 heads now have 3/8 rockers on them rather than buying 7/16 rockers for the new 210 i would swap out the 3/8 studs and my rockers and the stud girdle and sell my 195s with 7/16 studs.i dont want to fork out 300 more bucks into these heads for new rollers already expensive heads if i dont have to.would 3/8 studs and girdle be just as strong as 7/16 studs??