I know the rev limiter wont kick in until about 6k rpms on LT1s but where in the higher rpms does the motor stop making more power and whens the best time to shift, Im buying a shift light to install in the defroster tube hole on the A pillar and cant decide what rpm "pill" to buy. any help would be appreciated.

 

I've been told several different peak numbers. All of them are in the range of 5400-5800 rpms. I have my shift light set to 5400 right now, but I think you will just have to try shifting at different rpms to determine where your car peaks. Also, I bought a pill kit from msd and it included five pills at 200 rpm increments starting at 5000. You might want to get that.
Later,
Jason