After 300 bhp and with very heavy use the liners can crack if over heated. Ford Focus ST225 Blocks (Does Not Fit RS Blocks). You are buying a MLS Head Gasket & Inlet Manifold Gasket & Exhaust Manifold Gasket & 5 X Spark Plug Seals + 4 X Stainless Steel Block Mod Shims & Head Bolts.
