Depending on the rocker arms used, it may be necessary to grind off a corner on a couple rocker arms so the baffles clear also.

You have to grind one each side for the bolt boss.... I've had a set under my old boat, don't now why this set wont fit....

I used a cresent wrench to break the tabs off, and used a thick cork gasket along with the rubber seal. No grinding needed, plenty of clearance for the roller rockers.

Pure speculation , pcv - breather tube baffle is in different locations on different covers one in middle ,another off to side , time to steal some of the kids clay .

I think my problem may be the poly locks. Did not know they made short and long ones. Gonna check into that.