hi ian
you said when i bought the piston from you that it had to be a 1mm head gasket, question is, dose it have to be a soild copper one,if so were would i get one,
and is there a difference between wm20 and m20/21 gaskets
mark

email (option): markbrob1@hotmail.com

Hi Mark..To control gasket thickness the solid gasket is the far better option. Also they are more durable, much more reliable in performance and are reusable (unlike the original composite type). Apart from all that though, you will have to file out the gasket around the bore to match the increased piston diameter. M20 and M21 gaskets are identical..
TT John on this forum has had a couple of batches made..you should find him with the search function. If he doesn't have any left you can get one from Copper Gaskets Unlimited in the States..Google them or you will find them on USA ebay....Ian

Thanks ian

email (option): markbrob1@hotmail.com