MCAT verbal has nothing to do with DAT RC.
One is 95% tone questions (MCAT) and the other is approx 70% just finding factual information in a long passage (DAT)
There are 2 ways you master DAT RC:
1) Luck
2) get an attack plan for how your going to attack the passages, are you going to read it all then answer? are you going to "search and destroy"? are you confused and dont' know what your going to do (that was me) ?
The thing about RC is, its a skill you either have or you don't have. You will not be able to improve your reading ability in a matter of 3-4 months, cause it usually takes years.
I "winged" it when it came to DAT RC, EVERY RC test i ever took before the DAT I was always getting 14-16, so I was very frustrated and about 2 months before my actual DAT, I stopped doing any RC and just decided to relay on my luck. I ended up with a 19 on the real deal, 19 isn't great, but it isn't terrible either