Sorry for the slow reply my comp has been down.
Tuning will be basically the same process, but will be a different setting. as far as the machining quality the Dynamites engines are pretty good. You can use valve grinding compound to Lap the head and sleeve together if you fell the need. You can use Gage Tape to check Clearance or a Dial Indicator or Depth Gage if you have access to such tools.
The most common area you need to seal is the sleeve to block fit, I put a Fine Bead of silicone under the lip of the sleeve when installing it.