Yeah maybe. We had the large gal tank in both(was a requirement for my dad) over 40. I think the 5.7's were much more thirsty than the 5.3's. Another reason why I'd like to get a 5.3 instead.Maybe TBI 350's were harder on gas? Maybe smaller tanks in the older one? ?♂️ Both my 2000 and 2009 had 5.3's.