As someone who got both their undergrad and masters in MEEN at A&M, my recommendation is to buckle up. From the get go, testing out of that class is going to be insane. They're going to give a you a final and expect you to ace it outright to pass compared to the course being graded on a slight curve. A+ tutoring is really good and there was at one time a tutor who would meet one on one that advertise on the bulletin boards in the MEEN department building. Getting a testing key isn't going to help as much as you think, the professors are on to the fact that students pass those around. The test questions are supposed to combine concepts that normally you don't see combined to see who can figure it out.
As a side note, I would choose your grad school courses carefully. Most MEEN 600 level courses were way harder than MEEN 363. Half of the reason MEEN 363 is hard is that you're drowning in other work. In grad school it's a little easier to focus on fewer classes.
Best of luck.