cam help

i don't want to bore it to the point of if anything went wrong i would not want to buy a whole new head what i am saying is i want to know i have room to work and .060 is the max thats why i only want to bore .030 then shave 0.020 off the top but i do understand the amount of performance that it will achieve is miniscule its just to tune it up and make it sharper and i am only rebuilding the engine cuz its got 960161 miles on it and it has a blown head gasket (i just bought the car canada thanks giving and it came this way)