Many, many seasons with spray bars, no problems, a friend of mine has been running them at least 5 years longer than me, never replaced a single valve train part. No need to drill the lifter bores for this.
I do suggest running ball/ball end push rods though. And have cup adjusters..

[color:"red"]65 Hemi Belvedere coming soon [/color]
[color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]