I have a 4.8 with a tsp 220/220 581/581 cam, long tube 1 3/4 headers, vic jr single plane, and a 650 speed demon. Right now i shift at 6600 rpms. It still pulling hard when its time to shift. I feel like its still in the powerband but im not sure how much higher to turn it with stock bottom end. The motor is in a 3200lb car with a 3600 converter, 3.73 gears with a th350. I wish i could put it on a dyno and see the power band curve but i live in a rural area with no dyno access. How high are others turning stock bottom end motors?

 

I turned my old 4.8 to 7k at the track...

 

There have been plenty of people turning 7k on a stock bottom end. I have rod bolts in a stock bottom end 5.3, and will be turning 7k.