what are the advantages and how hard is this to do
I have before, I bought a degree wheel kit from summit, did two motors, honestly I wouldnt waste your time or money! One of the motors I did it to I had already been running and didnt notice any significant difference. You also have to modify your cam gear for different offset bushings, the different bushings will change the cams relationship to the gear. Its a terrible pain in the A@@, time consuming, unless your running a drag car, I wouldnt bother, I didnt degree my 468 I just built. Thats just my opinion though, some people might swear by it , not me.
it all depends on what you are biulding some motors need it some dont
i've built a few engines and have degreed a few cams. and degreeing the cam is really a waste of time. unless your trying to figure out if advancing or retarding the cam gains any horsepower through dyno research i wouldn't bother. just install the cam straight up as per installation instructions and you won't have a problem.