Maruha Metal Head Gasket Thursday, October 1, 2009 According to Mike at ABT, the stock head gasket was not a good match to the custom Wiseco 85mm pistons I purchased from Flyin’ Miata. I had read that the stock head gasket could fit “with careful alignment” and possibly “some minor trimming”, but I trust Mike more than the innernet. With an order going into Maruha anyway, and with the in-stock availability of their 86mm head gasket in multiple thicknesses, the decision was easy. We only needed a stock thickness gasket, so I ordered the 0.8mm thick version. This head gasket, along with the current deck height, should give us the exact piston-to-head clearance (squish or quench area) we are looking for. Incase you haven’t heard, it’s all about the quench!