I recommend you have your head work done by a shop, Plane the head if you are going N/A the stock head gasket size would be fine or maybe a little thinner, being your going N/A you would benefit from a higher compression this will give you more Horse power and torque. do not go to thin as you will still have to check clearance for you valves and pistons, These facts i am not sure about. ARP head studs or Metric blue Head studs to mount the head back this will give you more clamping force from head to the block, which if you should nitro or race gas it can handle the pressures of the explosions. tuning is what you need to get away from detonation which will destroy your motor. High octane fuel only when you are dealing with high compression. your motor i believe is already 10:1 which is pretty high but if your going all motor you have room for more compression. Like i said there is a lot you have to understand to blue print your head but if you just want to get more air in unchecked, i wouldn't recommend doing it yourself, there is a balance you want your motor to have and in the end you have more horse power, their are certain tools you need to have to check clearances and you have to know how to use the tools to do the job properly,like changing your springs you can do it but you want to have it checked before you re install the head and find that after all that work you have to pull the head back off, trust me i pulled my head three times doing my build and it isn't pretty. then there is experience that you need to be successful. Pressure check, they mount the head under a solution and pressurize the chambers and jackets to make sure you do not have any cracks that the naked eye can not detect. bubbles will indicate a leak. If you want more power and a good job spend the money now not later. as i keep saying there is even more to it you really have to understand how it all works to receive the information, even to ask the proper questions that is how deep it is. I have seen guys do the backyard head jobs and break parts on the head after running there cars to death and i told them the same thing i am telling you now. Know what you want to do to the motor first get even more knowledge than what i am telling you and decide what you want, call the machine shop , shop around, BMW heads carry i different price tag most wanted to charge me $750 to port and polish my M42B18 head so be prepared.