cylinder heads

Hi. I have a pair of World Casting Cylinder heads for SB Chevy, the S&R heads. I would like to know the maximum Cam lift that I can go, valve size, etc. The following numbers were on the heads:1-052 817
N H 91. any information you can give me would be greatly appreciated. Thanks, Doug tennison  

hello my name is justin and i am a sgt in the army stationed in iraq. i just wanted to let you know that we really enjoy your magizine out here, in my shop there are several hardcore camaro guys and some mustang guys so there is always something to talk about. keep up the good articles about fourth gen cars, as well as the new camaro coming out that a couple of us already plan on buying. if by any chance you have back issues that you arent doing anything with, we would gladly take them off your hands! we are limited on what the store gets out here. i will send a cool pic soon of us displaying your magizine in front of our helicopters. I myself have owned 2 fourth gen cars already and another guy has 1 second gen, 2 third gen, and 1 fourth gen cars already so there is a huge following for camaros and firebirds out here. thank you for your support.
                     SGT Mills, camp sykes iraq