A/C expansion valve
 

Will I be able to remove it from my 96 lt1 without going through the glove box? Can I just take the lines out and unbolt it and put a new one on the evaporator from the engine bay?

Yes, I just did mine a few weeks ago. Two Allen head bolts, not sure on the size, was easy to replace.

Thanks

It's in the engine bay. Put all new o-rings on it when installing the new one, get the system closed up as fast as possible to keep moisture out of it. Don't take it apart until you have the parts in hand to do the swap, and have it vacuumed out before charging it.