After running in I put the thing on a wheel dyno, [rolling road], & set the distributor at the highest power output, full throttle at 3000 RPM.
This gives me the best ignition timing at normal cruising speeds on our country roads around home.
I keep a regular check on fuel consumption. I fill the tank to the top each filling, & watch the usage. This tells me if problems are starting. An increase warned me a rear brake was starting to drag. A sudden increase from just under 9L/100Km to 14 L/100Km with no obvious reason sent me looking seriously.
I found the solder on the fuel sender/pickup fitting had cracked. The welds held it in place, but it was leaking. Not enough to drip or even smell noticeably. It was stained around it, but the fuel evaporated off as it wept out. When a full tank lost 2 litres in a week, sitting in the shed, I confirmed it as the problem.
Hasbeen