anyone know why indy used the 2.100 in. and 1.650 ex valve sizes? i'm more concerned about the odd 1.650 exhaust valve. why would they use that size when everyone else seems to use 1.60. whats the benefit with that large exhaust valve? seems like they would of had something like 2.08/1.60 as ryan once told me the 2.08 worked better than the 2.100 for some reason. anyway, just curious to what anyone knows about indys odd valve choices.