WD-40 and carb cleaner ok, or would that washout by cylinders and oil rings?
Use a plexiiglas scraper and some lacquer thinner to remove the carbon. Then vacuum the cylinders. Clean the head gasket surfaces with Scotcbrite and lacquer thinner. The valves need to be lapped and gapped too.
It would be good to hone the cylinders and replace rings. also replace old valves and grind valves and seats. If you still have the solid lifters, grind the stems to proper clearance using the piston height method. This method can be found on the book "engine" published by the club. Discard that old head gasket and replace it. Use a bottoming tap on the threads and if the studs look rusty, replace them. Blow out the bolt holes with compressed air.
Sorry, instead of studs, bolts.
Unless I'm wrong, it appears he's got just one two piece valve in it. And I might be wrong, they might have made two piece valves without the holes on top. I guess I've never heard of it.
How did that old song go? Oh yeah:
Shaving cream, be nice and clean, shave every day and you'll always look keen!
Different plug thread pitch on aluminum Z head?
I always put a few drops of thin oil around the base of each plug and I am seeing bubbles immediately, which means compression is leaking out of each plug at the threads.
I'm afraid to tighten more. Is a washer needed?
Warming it up with a drive before re-tightening.
Aluminium heads are re-tightened when the engine is stone cold.
I'm assuming the plugs in the new head are still pipe thread and not modern, then some have used plumbers thread tape to stop compression leak.
I use Permatex, Aluminium Anti-Seize lubricant.
Thank You, Frank.
Chris, remember that you have re-tighten aluminum heads 3-4 times or more when "stone cold" to get them to where they need to be. I do my aluminum heads at 45 lbs/torque. I go through the torque sequence until the head bolts don't tighten any further that specified.