Engine RPM?

I recently dropped in my newly rebuilt 318, 73 model year, with the stock forged rods, slight overbore, a very smalll amount milled of the heads and a XE268 cam(.477/.480), in conjunction with stock compression pistons. i run Hooker headers and a Performer intake and 600 cfm carb. The valve train (pushrods,shafts, rockers, ect.) are MP replacments. I am running the recommended Comp valve springs.

I have only turned this motor to 4,000 rpm so far, as I still only have 350 miles on the motor. For instance, when at the drags, what is safe maximum RPM I should shift at or allow the motor to rev to? I would just like some opinions on what people think is acceptable for a 318 with hotter cam and rebuilt bottom end with similar to stock components.