Not trying to slow the car down any, but if it does not that big of a deal as I bracket race. The backstory is I used to run 29.5x13.5 tires and a 4.56 gear. I always shifted at 6,000 would trap around 6500 or so. I than put 31x14 tires on the car and that brought the trap rpm down to around 6200-6300. I have since went from 440 source heads to Trick Flow 240's. I need new tires last year and I wasn't planning on doing any 1/4 mile racing since alot of stuff around me is headed to the 1/8th mile program. I went back to the 29.5x13.5 tires as they seem to work a little better and I wasn't concerned with rpms since I was only plan on running 1/8th mile. With the Trick Flows I'm making more power so the car is pulling alot better. Been out twice this year and I moved my shift point from 6000 to 6400 to try and bring the trap rpm down, but it's right around 6600. Engine is a .040 10.9:1 440, stock stroke, eagle rods, MP .557 cam, Victor Intake, 850 Proform Carb, 727 with 8" 5000 stall, Dana 60 4.56s, 3200lb with driver race weight. Went a 10.57 @ 125 this weekend. I suspect with the projected weather forecast and hot weather coming I'll loose 1-200 rpm going thru the traps due to the weather for the summer months. Prob will go back to a 31" tire next time, but don't really want to replace a new pair of slicks was just looking for ways around that at the moment.
As primarily a bracket racer i would shoot for absolutely the best consistancy you can get. Reduce the STR ( starting line ratio) with the tallest tire you can run and consider a taller gear. If you drop to a 4.10 ratio and go to a tall tire overall cosistancy will improve. The 1/2 shift affects et some because we are not perfect and even a slight rpm change means a little change in et. the later the shift comes, the more accurate you will be. Also reducing SLR and going big on tires will help you reach deadly consistancy. The cam you have is fairly small and reducing trap rpm to 6000 will pay dividends in a longer block life.
