Rev kits exert some pressure to the lifter body. Their "selling" claim is in increasing rpm before valve float but the best thing about them in my eyes is their ability to keep a lifter in its bore should something break. If the lifter leaves the bore, you lose oil pressure and the possibility of doing more damage is high.

Run enough spring pressure with your hydraulic and you won't have problems.... the rev kit is just a safeguard IMO.

-Mindgame

 

what does a collapsed lifter feel/sound like? after a quick 1st-2nd gear race with a mustang i got alot of noise/vibration from valvetrain. thought i broken a valvespring, they have 25k miles of hard use. but i changed the springs none were broke.... got comp hi-energy's

 

I have heard numerous people comment on the sensitivity of the comp r's. Going from 1/8 to 1/16 turn past 0 lash and they picked up 15 HP or something like that. Nobody even knows the correct valve lash on these as it varies so much. So unless you want to adjust your rockers five times or rev past 6300, get the comp replacements JMO.

 

i have lunati liffters, and ive had no problem and rev up to around 6700 rpms.....but thats an a4..so
i dunno...id go with lunati's