The FSM says to address cylinders with more than a 15 PSI difference. However, before you go and throw the supercharger in the trash and pay for an engine swap, that's the
IDEAL PSI difference. Running boost on a cylinder with slightly lower PSI does not endanger the engine itself. It just makes less power in that cylinder.
I ran the supercharger with the 2.1" pulley at 11 PSI on a cylinder with
60 PSI. The piston rings were worn out and allowing air to slip past but there was no ill effect on the engine itself. It just made less power. Install with confidence.
If you aren't sure if you should, take a look at the video of my dyno run on the first page of my build thread:
Jerod's Supercharged TRD Build - Toyota 4Runner Forum - Largest 4Runner Forum. Sure doesn't sound like an issue to me!