The '99 FLHTCU does have the TC 88 motor. My '99 Ultra has 72,000 on the odometer. I did a roller chain conversion about 2000 miles ago. The primary tensioner was toast and the secondary (inner) tensioner was about 50%. Before the conversion, after warmup, oil pressure was about 10 to 15 lbs. After the conversion, I run 30 lbs+ all day long.
It is important to have the tensioners checked. If they are worn, or, if you experience tensioner "flakes" in the oil, or if your oil pressure drops after the engine gets warm, you need to have this addressed. While the tensioners are being done, the inner cam bearings should also be changed to the Torrington units.
Member "TQ" of this forum, did a great writeup of the whole process including some great pictures. Check it out....