From our experience the reason for premature lifter failure on mostly CVO 110 is the huge valve springs they install from factory. They are triple heavy duty high lift springs. On my personal CVO when I did cams last winter I switched to kibble white .630 beehive springs and comp pro magnum lifters to go with s&s 585 cams. Also machined heads to raise compression to 10.5:1, now I'm at 110hp/122ft tq

 

Yellowbird speaks the truth. Do it before it's too late.

 

If I were to stick with the stock cams, would .630 or .600 beehive valve springs be the ones to use? Interested in the Kibblewhite valve springs also.

 

Here is some real life feedback from cvo owners:
https://www.cvoharley.com/smf/index.php?topic=106155.0

 

How much needs to be machined off on a CVO 110 motor to achieve a 10.5:1 compression ratio? What compression ratio will be achieved by installing .03 head gaskets?

 

Before doing any head machining or compromising on head gaskets, I would (and always have) buy a set of forged 10.5:1 pistons and high compression head gaskets. Maybe $350 tops for both and material safe so you can go back if you want to later

 

If your only worry or concern right now is noisy lifters perhaps it would be best to just address that. The twin cam ifters ar a weak point in the motors. Swap them out if you can. Something as simple as Chevy LT1 lifters (Comp Cams 850-1) are about $20 each on Amazon. Either remove valve covers and pushrods, or cut pushrods and replace with adjustables (HD SE adj are good ones).

But first consider your symptom: noise on cold start. Mine did that after about 7000 miles. I tried heavier oil, conventional oil, synthetic oil and so on. Even tried a whole bottle of STP oil treatment (made it worse).
Then I tried a thinner oil, 10W60, and the cold start issues went away. I believe the thick oil when cold takes just a tad longer to pump up the lifter.

This lifter noise issue is a big Internet fight but it is indeed a real issue. The bottom line is replace your lifters if your bike is out of warranty.

pm me if you want more info.