Looking at a 99 TA. Have Some Questions..

I found a 99 Auto TA. My first question is, why the 99 gets 23 highway and the 2001 gets 26..? (EPA Estimated) Something must be different..
What gearing is in the auto that year? (non WS6 if that matters)
Any common problems in the LS1 to be aware of? The car is a 1 owner and COMPLETELY stock, no mods have been done, so hopefully nothing has been messed with..
I've really been looking for a 6 speed because that's what my 93 is, but am having trouble, so the auto will do for now. I just need LS1 power
but..
1.)who cares what the EPA says, it depends on how you drive.
2.)Check your RPO codes for either GU5 (3.23) or GU2 (2.73).
3.) there is plenty of stickies to read and all the information in the world lays within the SEARCH BUTTON

I found a 99 Auto TA. My first question is, why the 99 gets 23 highway and the 2001 gets 26..? (EPA Estimated) Something must be different..
What gearing is in the auto that year? (non WS6 if that matters)
Any common problems in the LS1 to be aware of? The car is a 1 owner and COMPLETELY stock, no mods have been done, so hopefully nothing has been messed with..
I've really been looking for a 6 speed because that's what my 93 is, but am having trouble, so the auto will do for now. I just need LS1 power


