It showed idling around 12:1, and as soon as I opened the throttle it went >15:1 :O
I quickly realised that I'd been mucking around with KINJFLOW settings trying to lean out the idle a bit, and vaguely remembered reading something about idle using it's own injector pulse values - which would explain why massive KINJFLOW changes wasn't having much affect on idle mixtures

I set it back to my calculated value which resulted in 13:1 at part throttle, I better do a bit more reading before I try and tune this thing

But two 10 minute runs about half an hour apart resulted in an overheating engine again, so decided to try and sort that out.
I pulled the radiator and found that someone had used a nasty stop-leak product in it at some stage, most of the pipes were clogged so started cleaning it out.
While that was soaking, I replaced the water pump, although the new one looks pretty crappy.
The mating surface was nothing like flat, and the pump was full of swarf from the impeller housing machining - not loose chips, but they'd be in the coolant within a couple of minutes of running

Next, I found that half my 2-piece top radiator hose was slightly larger diameter, and was leaking under pressure so replaced that.
Then tested the thermostat, it was barely opening at 95 deg and sometimes not opening at all by 100 - bugger. And when it doesn't open fully, the bottom plunger doesn't close off the radiator bypass hose - so water just circulates around the engine

I removed the thermostat (had to break it out of the housing) and blocked the bypass hose - replacing the thermostat will probably involve machining up a new housing

So put it all back together once the radiator was unblocked, I'm hoping that's the end of my cooling issues.
Next I popped the cam cover off to fix a small oil leak, and thought I'd check the valve clearences while I was there.
They were all far too tight - plus the bearing caps were in bad shape, most of the buckets could do with replacing, and one of the shims was cracked.
One of the exhaust shims looked burnt, so guess there's a valve that hasn't been sealing too well. I'm going to put together a leak-down tester to see if I can gauge the valve conditions.
I've got a slightly warmer set of cams that I'd like to put in, but they're a bit rusty so I've got them in an electrolisys bath to see if they can be brought back to life. If not, I'll pick the best set of standard cams I've got for now.
So this afternoon's job is to pick the best set of cam bearing caps, buckets and cams I have on hand, and try and shuffle shims around to get clearences right.