Let me use the best knowledge that I've been consumed by reading...You wear 14 lbs lead. That should = 14 + 11 = 25 lbs of lead if you are wearing aluminum tank. I read somewhere steel tank is 11 lbs heavier than aluminum.
Oh goodness... this is why the old adage "measure twice, cut once" has existed for so long.
Be careful what you read. In my experience, a steel 85 and an aluminum 80 weigh about the same (i.e. if you have to carry one to the car or boat), but the aluminum tank is more buoyant because it displaces more water... i.e. the steel tank has a slightly slimmer profile.
The difference in profile means the aluminum tank displaces about 6 pounds more water than the steel tank... so the aluminum tank is about 6 pounds more buoyant. Which simply means that a given diver using the aluminum tank can shed 6 pounds of lead if they switch to using the steel tank.