supergass

I have a 69 Camaro backhalf footbrake car. It weighs 3450 with me in it at 208. It has 1900lbs on the front and the balance on the rear for a wonderful weight dist. of 54.5 on the front with a 540 BBC. It is a ladderbar car set at 0degrees or level. I have afco double adjustable shocks up front (BNC) shocks (big nose compression) to controll the landing. I run the moroso front springs with great stored energy. I am just not so thrilled with my consistency. It runs 630s at 111mph. The 60ft is 1.42 with a 1.76 glide. I have M/T 17x33 with a huge 23 inch cross section and a super soft sidewall. I tried them after the 16x32 goodyears with a stiff sidewall. NOW the rub is my friends run 10.5 tires with close to the same ets and there cars are deadly consistent. THE only thing I can think of is my car seems to rev up a little at the shift point (not real firm) which might be why my mph is 5mph more at the same 60s and et. I wonder has anyone every seem such a thing?? The engine has tremendous torque, has anyone had clutch pack problems from the glide??

Thanks for any responses!!