I saw the same thing,, believe it is because these engines are so under valved,, going up in valve diameter slightly to the engine builder sized valves does not hurt velocity much, but adds capacity for better breathing at higher RPM,s

I know I am late to t his party, but am wondering if Dad Truck with his computer programs, or other informed engine builders can shed a little light on my current engine. When I built it for turbo, the cam grinder suggested widening the LSA to avoid blowing raw unburned mixture out the exhaust. So he took a basic RV grind that had a 110 LSA and widened it to 113. The question is, what would that do to the characteristics of the engine now that it is NA? Head is ported with oversized valves. I understand from reading here that 106 is probably more in the ball park for what I am trying to do. Thanks for any insight.

Sam

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Thanks for the info.

Sam
concerning comparing LSA narrow and wide,,

this chart says it clearly

http://www.compcams.com/Technical/FAQ/LSAproperties.asp

the reason for running a wide LSA is because you had the motor turbo'd.
the turbo would overcome the lower lower torque, lower dynamic compression ratios with a higher effective compression ratio.
without the higher effective compression ratio, your engine may still perform fine,,have good manners and a wide power band, but you are likely leaving some potential performance on the table.