Ok well I had the carb in the kitchen sink and gave it a good jetting all over with carb cleaner. Re-fitted it and it hasn’t made a spot of difference. In fact it seems to be getting slightly worse as time goes on as it’ll only idle for a 10 seconds now and then just gives up.
I’m beginning to think the problem is electrical. Possibly distributer or ignition coil. It’ll get the leads, plugs, dizzy cap, rotor arm and coil from central autos. If that doesn’t fix it then I know somewhere not too far away breaking a K10 so will go get the dizzy and carb. If it still doesn’t work after all that then I’ll set fire to it and see if that helps.