Hi all.
It's been a while since I got anything done due to the weather down here.
I used a cable tie through the spark-plug hole to find top dead centre of each piston and set them all at 0.025". After I get to give it a run and warm things up, I'll check them all again.
The gaps were more than twice what they should have been.
I hammered all the dings out of the tappet cover and cleaned it all back to bare metal as much of the paint was gone and it was pretty rusty.

Under the most recent coat of grey paint, I found that it used to be painted gold. You can just see a bit of it on the left end in the pic above.
After stripping it back, I gave it a few coats of gold high-temp engine paint and left it to dry for a few days. After that, I fired up the barbecue and baked it for an hour at about 150°.
It was supposed to be 93, but even with just one burner going, it crept up. As you can see below, it came out alright.

I found that the new cork gasket kept trying to move as there is no groove or bolt holes to locate it. I used a bead of high-temp RTV silicone
around the tappet cover to fix it in place and used pegs to stop it moving until it set. After it was dry, I cleaned off the bit of silicon that had oozed out
and coated the side of the cork gasket that contacts the block with a aviation gasket paste #2, which is a non-setting type.
This way I don't have to worry about the gasket moving and losing it's seal, yet I can still remove the tappet cover to set valve clearances without wrecking the gasket.
Before I can give it a run again, I have to refill the black drum with fuel. What do you all suggest I use as additives?
I know some older engines can handle unleaded without an issue, but I know my old Holden had to have some sort of lead-replacement additive or it wouldn't run properly.
I'm not planning on leaving the fuel in the drum long term, so I'm not worried about fuel stabilisers.
I'll use it in the chainsaws and the mower, if the weather ever fines up, and just get more when I need to run the truck.
Thanks.
Greg