Use one of the dremel flex cable extenders so you don't pack the dremel full of conducting dust. They last longer that way.
We use the dremels at work to make tiny stainless medical device parts and that's the only way we get life from them.
Ben , I did the valve guide replacement and valve seat grind thingy. Need a nice long step drill for the guides, and an oven to heat the heads. Step drill the guides from the chamber side and knock out. To replace, simply heat the head and using a stepped rod, pound the new guides in.
Oh yeah, distrust the guy you buy the guides from and measure them before you punch the guides in. Failure to do this results in a cracked head. Ask me how I know
Had a coupla simple steped punch tools made to do this- 1 1/2 od rod with a section turned down to the valve guide ID. Do it on a lathe.
As per the seats, bought several valve seat grinding stones at the correct angles and different grits. Get a threaded rod to fit into the center bore of the stones. Use 2 nuts and washers to lock the stone onto the theaded rod. Turned down a front section of a threaded rod to fit into the valve guide ID. Fit the turned portion of the threaded rod into the guide to align the stones to the seat. Turn the threaded rod by hand and reface the seats. Doesn't take much pressure. Stones were about $15 about 12 years ago. Oh yeah, intake and exhaust valves are different OD and you will need 2 different punching and grinding tools.
Bought new valves, dychem blued the seats, put a dab of grinding compound on the valve and got a perfect match.
Ken