Hey all quick question I have a 426 I went to a track on it for the day and put her away under a cover in the garden she was fine then but 4/5 weeks later I've gone yo go oout and the clutch is slipping. I'm thinking its moisture in the oil does this sound OK and if so how can I cure it

Ok why would there be water in the oil? Not sure about your reasoning but if you feel that's right then your options are drain the oil and refill, should cure it if that's what's wrong, or check the clutch action to see if the cable or lines are broken or trapped, finally take the clutch cover off and really see what's going on. Not much else comes to mind. Hope you get it sorted but still unsure why you think it's water just cos it's been standing in the cold or has it had water pouring over it for weeks cos even then most engines are pretty waterproof if they weren't then if water can get in then oil can get out.