My name is Yannick, owner of a ZXR 400 built in 1992 (same built year as me

I've got 2 of the same engines, one with a problem and the other one with an issue. Winter is coming and with winter comes the time for repairs and maintenance.
The issue is actually a question; going to replace the CCT but the original CCT of the L2 model (1992, part no 12048-1096) is out of production and nowhere to be found for sale. Taking a look at the schematics of the Camshaft & Tensioner of the L2 model (MSP and others), it shows a separate CCT for the L3 model (1993, part no 12048-1125) which is still available but some of the website which sell the CCT show that it doesn't fit the L2 model. I just want to be sure the L3 CCT fits the L2 model, before ordering.
The other engine makes an agonizing metal on metal sound at a specific amount of rpm, 6-7k. While riding it, it doesn't seem to be that hard of a noise, but when revving in neutral while standing next to it, it is deafening. Started out as a small noise and got worse and worse, hope I didn't kept driving for too long.
Before starting to rip the whole engine apart, it would be nice to know where to look for.
Greetings,
Yannick