Fingers crossed the new O rings have stopped the heater pipe flange leaking, ran the engine up for ages to make sure, got a noisy tappet on one cyl but it stops if the revs are picked up slightly. Exhaust smells like high hydro carbons but if so the engine light would come on ? Thermostat opened this time as had to top up coolant a lot, fitted the dash back in so can finish that tomorrow ,