What recommendations would you recommend for a stock TR4 engine with 87 cylinder liners? I have heard that the head gaskets for the standard bore 86 cylinders will result with the gasket extending into the combustion chamber, resulting in shorter head gasket life. There also seems to be significant variation in prices for the copper clad gaskets. Does higher price correspond to better quality. BPNW has a cylinder gasket (Head Gasket Set Big Bore 87mm to 90mm) which is described as providing a better seal without extending into combustion chamber. This gasket is described as "made with a perforated steel core and and elastomer surface that heats very evenly for a superior seal, plus the fire rings are made from a stainless steel. No blown head gasket with this head gasket". Would this 87/89 gasket provide any real benefit to justify the significant price difference?