what is the difference between corvette 1lt and 4 lt

Assuming that you're talking about the 2005 - 2013 Corvettes, check out the various model years at the Corvette Action Center and take a look at the ordering guides which explain the different trim levels: http://corvetteactioncenter.com/specs/c6/index.html

lt4 has 4bolt main and powder coated red intake lt1 usualy 2 bolt main unless customized

Margaret, We can provide you with more information if you email us at socialmedia@gm.com. Also, can you please let us know which model year you are referring to. Erica Tiffany GM Customer Care

A 1LT is your basic Corvette, the 4LT is a fully loaded with most convinience options included in the car. I recently purchased a 3LT and it literally has everything in it except the Navigation, and two toned seats which come in the 4LT.