Cars Need help editing a modded car

[BoLjutch]

Recently I downloaded a Z31 add on car for AC, but It replicates the Z31 300ZX Turbo. What I've been trying to do is edit the power.lut and drivetrain.ini to replicate a JDM spe Z31 200ZS or ZR. The base mod works, and I copied it to keep the base Z31 300ZX. But the moment I copied it and edited the power.lut and drivetrain.ini, it broke it entirely. I'm getting errors of outdated tires, sound needing fixing, just a whole mess of it. When I attempt to fix it through CM it gives me errors that it can't fix it for some reason. Can someone please help me?

Update, I did manage to get the car to be error free in CM, but it doesn't work when I try to drive it, it says it fails to decrypt the .kn5 file for the car and that it won't look right.
Update 2: This is what happens after I've tried adjustic the power.lut after unpacking data.