Burnt Exhaust push rods

Have a 526 with BAE Fathead 4”s. Very few problems with the exhaust push rod/adjusters. Lube before start, adjust valves and lube adjusters between runs. But this week end did my 6K RPM burn out (rev limited by MSD) goofed on the lights and idled down the track. When we took the valve covers off found #2, #6 and #8 pushrods/adjusters burnt. I replaced the push rods/adjusters, made a pass, 6K burn out, 8800 thru the lights and no problems with exhaust or intake. What is the difference in the oil paths? Any suggestions what to look for?

TX's