Now your talkin'!! trucks are for haulin' stuff(not all of them don't bash me if you have a fast truck that hauls ass)
How much compression and what is the duration @ .050 of the cam? also lsa? I think the carb is a bit on the large side for a 383....if the cam is matched to the rest of it and it has decent compression I'd think you would be in the 14's for sure.
p.s How are you gonna get the trans am to 300olbs? It is a bunch heavier than that stock.
I was kidding with the 14's I think mid to high elevens should be fairly easy.