Ive got my block together and my heads are coming back from the guy who is porting and polishing them on thurs. so im putting my roller rockers on my new shafts that i got from falcon. im using comp cams roller FE rockers. and my question is this. The comp cams rockers have two oiling holes that are on either side of the ring grove midway through the bore that rides on the shaft. on 8 of the rockers the holes are front left and rear right ( if your holding the lifter right side up and the bearing to your chest) and the other eight are front right rear left ( exactly opposite as the other eight) NOW IM GUESSING that this is to off set half of the lifters getting oil half the time and the other half of the lifters getting oil the other half of the time. maybe this is correct maybe not.
1. If any one has a service manual could they check and let me know if any info on this for stock mel lifters.(sorry i need to get off my ass and get a manual)
2. if anyone has done this set up and figured this out let me know
3. If anyone is just tooo smart for their own good and knows this for no reason other than they just know this because thats what they do is know stuff((kultulz)) please let me know!!!! (kultulz is the man..sorry i couldnt help it)))

Im a little confused on your question. You started out talking about the Comp Cam Roller rocker and then call them lifters. While describing the groove and hole for oil right side and left.
If it is in the Roller rocker, I was told the groove was added in the last few years by the manufactures due to customer requests. The groove is to help pool the oil some in each rocker and the holes are for oiling the roller and pushrod. The 8 are different as the adjustment bolts are made again by request to have an offset to help in aligning the rocker and pushrod thru the holes in the intake manifold. So the oil holes are drilled differently because of the offset bolts interferring with the drilling.
Sometimes the holes hit the grooves and most of the time they don't. I was told that if they dont it helps the oil pressure in the rocker assembly. But some engine builders use a die grinder to groove and connect them. Believing that it doesn't matter.
In ending this long story, it's what you want to believe in your engine building experience or trust your mechanic's knowledge. I for one who just sells them and never had a return or heard of an oiling problem in 5 years believe that they have plenty of oil to handle heavy racing and just cruising around. Just look for the 2 holes and besure they pass all the way thru.
Good luck John