Am I allowed to reenlist for 7 or 8 years instead of 6?

Six years is the maximum reenlistment length. In addition, unless you are promotable your current RCP is eight years, meaning you could only reenlist for five years right now.

Unless your new MOS is offering a massive bonus, you should reenlist for the minimum time. Being in your reenlistment window allows you to pick a new duty station and PCS at two years on station, versus the three years on station if HRC moves you. Or to stabilize at a location you like once you are there

Why in the hell don't you use your retention NCO? They are directly hooked into the system, get the latest retention news/MOS's etc. By the way when I was in i was only 2,4, or 6 max, regardless. Beside you wants don't matter, you should have figured that out by now.

You do have a Subject Matter Expert (SME) in your organization who will give you the right answer based on your circumstances: Career Counselor.

The generic answer is: depends. What’s your reclass MOS and it’s requients, current Time in Service, Amy current DA applicable policies that might affect you, etc....?