Originally Posted by
blindsquirrel
Your existing 2010 Camaro OS that will never be able to talk to a T42 (not even a 2010 Camaro auto can talk to a T42, as all those used T43) can be SPS-flashed to turn it into a 2010 Silverado that can talk to a T42, as they use the same service number 12633238.
If you decide to use the Express van OS instead, that will require a different service number ECM.
I don't know how to tell you which one to use, because I don't know which pedal/TB you have since you didn't say, and I don't know if a pedal that works with the Camaro OS will also work with Silverado/Express.
All T42s are the same. There are about 300 different service numbers and they all interchange. The TCM can be write-entired in HPT to change OS/platform but if you have to get the ECM SPSed why not do both at the same time? Lots of independent shops these days have 3rd party scantools/passthru devices and SPS subscriptions and can reprogram modules in-house, it's not just a dealer-only thing or specialized tuner shops anymore.