ok my car has the auto transmission with the 2nd gear and up so i was told i had the 273 gears.....if i put 373 would this wear and tear anything on my car or damage anything serious...is this safe on the cars motor and tranny?

 

you should be completely fine. jus get it done professionally.

 

for everything in the driveline forward of the new gears,they would have less stress as they now have a better mechanical advantage against the vehicle.For everything after,just the opposite.

 

I went with some GM gears and had good results. The wear and tear are not that significant and I would not worry about it.