I believe the bolt size is 5/16unc can anyone tell me how long they should be and what grade tensile strength I need.

Cheers

I don't know the length off-hand, but if you put the cover on the flywheel and measure the total thickness then you won't be far wrong.

I bought my last set from Burtons - just looked in their catalogue, and they're 20p each + P&P + VAT (FP518)

HTH,
David