When to shift?

I ran that exact same cam in my 360. With 1 5/8 headers I shifted at 5700 rpm's with stock J-heads. With a 10 inch street fighter converter and 3.91's (28 inch tall tire) I hit 12.9's at 104 mph. I drove it 1 hour to the dragway, raced it as I drove it. Never uncorked the headers, just ran it as I drove it.