blankt

ok im not sure if this is the correct place to post this but here it goes. im looking at this 98 trans am with a stock lq4 with long tubes in it and rebuilt trans with shift kit and 2800 stall. i know the stall is kinda small but my question is there going to be a difference power wise between the lq4 in there and a ls1? and what about gas mileage between the two? i have a bolt on 6 speed ta and get 18-20 in town and 27ish highway so will the lq4 be similar?