Thanks ChinaV! I hadn't thought of that -I have been relying on the timing mark which was spot on. So if I use a screwdriver down the spark plug hole method, I rotate the engine and then when the screwdriver is a at its highest point, that will be TDC, am I right?
Also,do you know am I doing the right thing with the guage, i.e does it need to go all the way through the gap for a given clearance, or just half slot through?
Thanks for your superspeedy response with this!