I have a set of vortec heads that I had modified. The machine shop machined them for .600 lift, put in screw in studs, new springs, and push rod guide plates. I understand that with the vortec heads you need to have self aligning roller rockers. Will push rod guide plates eliminate the need for the self-aligning version. What roller rockers should i get.

 

due to the centerbolt valve covers, you'll need narrow-body rocker arms. If you want aluminum full-rollers, I think all of these on the market are "rail" rockers, so you'll hafta replace your guideplates with washers the same thickness. Don't forget the LocTite.
If you use rockers like COMP Magnums, (not Pro-Magnum) you can use the non-rail type and use your guideplates. But using guideplates requires buying hardened pushrods.