I was on the phone withg Red himself yesterday talking chips..
He told me his 107R has 3* less timing than the 108Rs which is 26*.. He went on to tell me that with all his race chips he pulls timing back (around 3*) as the car approaches 75 MPH or so.. So while 23 or 24* is the maximum timing in the 107R it isn't all the way through a full 1/4 mile pass in his chips.. I think the decrease in timing once the car approaches the higher speeds is to maintain the ability to run a high boost setting with the car under severe load (which they are) in the top half of a pass...