At one time is was .004-.006 for all their OHV engines. Then they decided part of the kickback/adjustment issue was the result of the gap being to wide, so they changed it to .003-.005 on the intake, but left the exhaust at .004-.006. Then as new models came out they new spec called for a .005-.007 on the exhaust. So basically if you set the intake at .004 and the exhaust at .006 you will cover all the larger OHV specs.