Worst case valve-to-valve clearance measured all of .030"! But changing from 108.5 degree lobe centerlines to 112.5 degrees (easy to do with dual cams) improves the situation to about .054". Surprisingly, engine simulator software shows very little change to the torque curve from the centerline change- if the software is to be believed. Anyhow, I'll be cautious and set them @ 112.5 initially, at least.
Jack,
You might consider running the intake @ 108.5 and the exhaust @ 116.5 to preserve your valve to valve clearance. If your simulation is PipeMax, there will be little change, if any. I like to see valve to valve clearance @ overlap somewhere in the .040" plus range, depending on how much I suspect the valve will "waggle around". Spintron testing has made me "cautious".
My experience with 2v and 4v DOHC engines is that advanced intake events (~2/4 degrees) improve Tq, at little to NO top end penalty, as long as exhaust events are also advanced a similar amount. This is of course, all subjective, and engine types DO vary, so it might not work. But at least it is an option to try and as a side benefit, exhaust valve to piston clearance is increased. Intake valve to piston clearance is, of course, decreased by advancing events.