1985-1995 Polaris ATV and Light Utility Hauler Service Manual, Page 267Get this manual
ENGINES Engine Service, 350L400L Reassembly Note: It is important to note that the 350L head gasket should be reinstalled with the wide side of the fire ring down, and the single round hole of gasket (A) beow the coolant elbow cavityThe 400L head gasket should have the word UP (8) toward the cylinder head and the tab (C) toward the exhaust, matching the tab area on the cylinder350 Head Gasket pictured at right
400 Head Gasket pictured at rightNOTE: Small hole in cylinder above exhaust port is decompression aid for starting