RE: HD Lifters?
I have the S&S lifters on my bike, seem to work fine. Also, when you have your gear driven cams installed, consider installing an S&S reed valve at the same time. It will correct any oil blowback coming from your air cleaner. It's a simple install while they have the cams out.
2003 Road King Classic EFI, white pearl.
S&S:.510G cams, lifters, pushrods, and reed valve;
V&H oval slip on mufflers, Ness "Big Sucker" air cleaner, Power Commander.