Installing residential toilet

[09Montanaliving]

Hello all!
I’m new to the forum, well, I’ve looked around a lot for quite sometime but never actually joined. Finally, after being unable to find an answer to my problem I figured I’d join the family!

My wife and I are planning on living full time in our 2009 3400rl and as we prepare for it, one of the tasks is to replace the toilet with a nice full size comfortable unit. I plan on taking on the task as I have been handling the other repairs/upgrades and feel comfortable taking on projects such as these.

I took some measurements and found that I would be fine with a 12” rough in toilet. I plan on picking one up tomorrow at Lowe’s. While there, I plan on picking up the other things needed such as a wax ring, or one of those new wax-less rings that people seem to love from what I’ve read in reviews. I also plan on getting a 3/8 compression supply line.

This is where I have a questions. I have been looking online to see what kind of plumbing our trailer is running and I have found multiple people claiming different things. Some say the unit is running 3/8 pled while others say its false. Now, if it is false, I will need a different supply line. If it isn’t then were all good! I was hoping one of you out there could please confirm for me.

Also, I’m sure many of you have done this modification/upgrade and have some advice or tips. If you do, please share them as I would like to only do this job once, but do it right!

Thank you!