Hi, I am after a good gasket set that has all the parts required for a top end build on my 1973 CB500, I have been advised on the UK site that I would need different size `O` rings due to the change of head gasket from the original. can anyone advise what size and recomendation of where to obtain these from please? maybe @hondaman could advise or suggest?
thank you in advance
John, UK