I believe the LT1 is to shift at 5700 rpm at the stock setting. I can raise or lower it by around 600 rpm's. What is the safest maximum rpm i can run on a stock motor? I have a supercharger so i want to drop my 1/4 mile times without damaging the motor. I get severe tire spin in 2nd gear so i wonder will that get worse if it shifts higher or better?

 

I run my 100% internally stock LT1 to 6000 rpm and havn't had any problems yet. I normaly shift it in the 58-5900 range but I've nailed the limiter at 6000 more than a few times doing burnouts and such. I don't have the ***** to rev it any higher.
Aside from that, stock LT1's don't really make much power that high. So I highly dout you would see any gains from shifting higher.

 

With the supercharger, the higher the rpm's the higher the boost so it is when the car makes the most power by far.

 

my friend revs his m6 lt1 to about 6300. no problems yet but seems a little high to me. btw it has 120k miles on it. my car has 180k and i shift in the neighborhood of 6000, no problem yet