Your 82 240D has a plastic 17 gallon tank.
If you are going to the trouble to remove it, find a tank out of a 300D.
They use a 21 gallon tank.
It will increase your range by 90 miles or???
You may not have any crud in the tank, the sludge you found is from years of accumulation.
You ought to pull the tank screen, it could be gunked up.
I actually found a tank in PNP from a 85 300D they forgot to poke full of holes.

.
Pulled it and it was squeaky clean. The sender though was gunked up.
240D up to 79 used a 21 gal tank then in 80 they went to a 17 gallon metal tank.
I know 82 83 use the plastic one not sure of 81.
I cut up the plastic tank with a Skill saw and threw it in the recycle.
Charlie