lifter orfice direction???

[cswan]

I am putting new lifters in my 99 suburban 5.7. I have done several flat tappet cams in the past.
My question is ...On the roller lifters does it matter which way they are inserted into the bore? Does the orfice on the side of the lifter point towards the front of the engine or the rear? Does it even matter?

I didn't even think to pay attention when I pulled all the old ones out.
Any help would be much appreciated.
Thanks, Carl

[maxwedge]

Welcome to AF, may be a dumb query on my part, but do the lifters have a recess around the circumfrance of the lifter where the oil feed hole is, if so orientation for the oil feed is not an issue.

[cswan]

Yes there is a recess. I was kinda thinking the same thing.
Thanks for the reply.
Carl