Originally Posted by 
Bulletman
				
			 
			Thanks 101RRS,
The piston crowns are not flat they actually have 4 x half moon indents which align with the outside half of each valve so i think as long as the valve stems are straight on impact there will be very little impact to the piston crown outside of the indents in the pistons.. i had 6 smashed rockers on 1 head and 3 on the other yet to the naked eye there is no noticable impact damage between piston and valve.. not saying its not there with bent valve stems but if you didnt know what had happened you would say the head has no visable damage.. 
which begs the question as to how many failed oil pump engines were just tossed because of what was assumed may have been internal damage.. that is for another thread anyway..
I will eventually get around to stripping the heads down to see if its terminal but from what ive seen the rocker gear seems to be the weakest link and it could be a smart design feature... but who really knows..
Cheers Bulletman