I have a few lifters making noise until well warmed up

is the noise bank specific? Like say the left side or is it both sides? If it seems centralized to the left bank there is a plug in the rear of the lifter bore that I have seen missing and/ or loose. This plug is sometimes missed or not tightened on rebuild. If you pull the dizzy out it can be seen through the hole.
http://www.forabodiesonly.com/mopar/showthread.php?t=266852

Second the 4 bolt cam thrust plate the secures the camshaft. There are two lifter bore plugs behind there, or not, I have seen them both ways w or w/o.
best to read about it here. http://www.forabodiesonly.com/mopar/showthread.php?t=175598