Lifter retainer trays mod

I was reading book i'd picked up a few months ago. (How to build high-performance chevy ls1/ls6 V-8s. I was reading where the cut 1/2" hole in the lifter trays. Has any body done this mod to the lifter trays???
http://i241.photobucket.com/albums/f...8/P1000598.jpg

i think i remember saying this was a bad idea...i could be thinking of something else though...im sure someone else will chime in