lifter tick?

[JDMark]

so after running my engine really hard at high rpms, it ticks. it goes away a little bit afterwards. i was told it was lifter tick, and my friend who had the same problem (and same engine) said when he changed his oil from 10w40 to 10w30 it made it go away. im running 10w30 tho he said it was the valvetrain gettin starved of oil for a little bit, causing lifters to tick. what could i replace that would eliminate this problem? oil pump? eh?
its an SOHC engine with 170k, just redid my timing chain (it did it before that as well). what do you all think? thanks
-mark