The 22re, like any efi engine can suffer performance issue from a number of things, and you may not need a rebuild.
What leads you to believe the engine needs a rebuild?
How many miles on the rebuild?
The biggest performance upgrade you can make to the 22re, is a gear change, with 33's you should be running 4.88 gears, the 33's are 15% taller than the stock 28's, and the 4.88's are 16% lower than the stock 4.10's gearing. If you were going to do a lot of towing wit