Larry, To start I currently run a gas gas and have for the past many years. Before that that we ran a 2001 and older version of the Honda with very good results . I have never ran the case induction Honda. It was Anderson prepared with Dellorto carb, Anderson pipe and silencer (very quiet), digital PVL non programmable with Anderson ignition curve. (stock Honda ignition curve is the worst for our application), Stock Honda piston with stock clearance. I think it is 2.5 thousandths. any time we put a new piston in we always ran 2 to 3 easy sessions for break in. Head volume I think was around 22 to 22.5. v force reeds. Top end with ours was a matter of keeping an eye on the bottom edge of the skirt at the center it would start to crack. time of this to happen varied. I will say RPM was the key to making them last longer. if you kept it under 11000 things last much longer. over 11000 and I was replace much more frequent. I am no expert on this stuff. I always left the motor setup to the engine builders. I just replaced parts as needed.
You guys are very lucky to have your own expert right on here with Ian. He is very knowledgeable and willing to answer almost any questions. and is spot on with his answers.
as Anthony said above getting your chassis to carry more turn speed will do much more in cutting your lap times than anything you can do to the motor.