different degree locks/retainers on different valves
 

I just heard someone tell me that their engine builder is using different degree locks on different valves For example the intakes are using 10 degree locks / 10degree retainers and the exhaust are using 7 degree locks / 7 degree retainers all on the same cylinder head. or vice versa
It kinda sounds like a good idea to give the heavier intake valve more locking angle, but why not give the exhaust the same holding power (IF this is the reason) have any other engine builders done this? articfriends MILD THUNDER mike tkach ICDEDPPL