question ?
Weather will play a large roll. I don't think you will have the 60' for it, you don't make enough power to make up for the lack of 60'.
I'll say 12.2.
Edit: it is a z28 however which weighs a bit less.... Plus you took a little weight out. I'll give it a 12.1 flat, maybe 12.0. I think it needs a little more converter personally.

