recommended cam for a 5.9 magnum?

THE 276 or 270 are also the two that i would run. as you said tis better to err on the side of caution on camshaft selection. IF you want more power later you can keep you eyes open for some used viper 1.7 rockers arms which will increase your lift about 7 percent or so if I REmember correctly. . Running a thinner gasket is an option to help raise your compression ratio a little, however i would buy an inexpensive tool to measure for your lifter preload because when you have a thinner gasket you will be changing the lifter lifter preload and it may be borderline now and even a few thousandths could change the preload clearance enough to end up with noisy or ticking lifters. save your head gasket money for nitrous.