what cam to use in a zz4 small block
 

I have a 350 zz4 that I suspect has a flat cam due to poor performance and backfiring through the carb an exhaust. I will be checking the rocker arm lift on all valves to determine what the cam looks like but if I need to replace the roller cam I am not sure to just get a GM replacement ZZ4 cam and lifters and assume GM has the best street performance cam out there or does anyone have a better selection or idea that would be a good street cam to perform up to about 6,500 RPM with a 5 speed. I am also wondering if I should stay with hyd roller or go to a solid roller cam.

It would be unusual for a hyd roller to go bad. Or some one did swap out the cam for a flat tapped. Check the rockers to see of all are working and if they are start looking at plug wires and distributor as the problem. Do the simple thing first.