This is a new cylinder spacer plate kit for the ATC250R 85-86 & the TRX250R 86-89. This kit is to be used with the following engine setup. You must run the TRX 87-89 style crank & the 1986 style TRX/ATC piston. This plate raises the cylinder up to make the port timing proper. This style setup was most commonly used back when the TRX was raced. It provides better overall power. This kit includes the aluminum spacer plate, 2 base gaskets, 4 longer base studs with nuts & 2 dowels. Free shipping is the US only. Thanks