How much cam shaft

I had a 508 lift, 312 dur. hydraulic cam in a 340 with 10.75-1 comp. and used the stock rockers and shafts. Driven on the street almost everyday and did a lot of street racing. I broke several things but never a problem with the rockers.

The 508 was the biggest hydraulic you could get from Direct Connection, after that they were all solid lifters. I wouldn't try to push the stock ones much over 512-525 even with adjustable rockers.