Speedway Tech Talk - Valve Cover Oil Filler Cap
Speedway Motors has a solution for those of you running a system where you have to pull your oil breather to add oil to your engine.
Speedway Motors has developed an aftermarket oil fill cap that is universally applicable. Rather than hunt down a valve cover that has been built (hopefully) with an oil fill port, you can pick up one of these instead.
Simply take your valve cover off, and after marking your start point with a center punch,start drilling with a 1-3/8 step drill or something similar. After you've gotten your hole drilled to the appropriate diameter, loosen the 3/32 set screw on the internal portion of the base.
That bottom portion threads onto the outer portion, which is fitted with an O-ring. Once those two halves are threaded together, Pat suggests applying some thread locking compound to make sure the set screw doesn't work loose and fall into the valvetrain.