As you've been seeing, weight is probably a good thing in land speed racing. It can aid in stability -- and also can add speed. You gain traction without the need for a wing, for instance, to make downforce -- and also to make bad aero.
So for a specific example, even if it is on a bike -- my ZX12R nitrous bike was spinning the tire around 200. I added 70# of lead to the swingarm -- and gained 7 mph.
Don't be afraid of weight, although you should be aware of what it'll do depending on where you put it.
Weight might not be as good at Maxton as it is at Bvile, because you've got good traction at Maxton - and only a mile to accelerate. At Bonneville you've got at least two miles before you even get into the lights.