Really cool stuff going on here! Not stoked on the amount of fine tuning needed but that is what will make my build mine. Not sponsored. Follow me @idratherbejeeping
I would paint it all with "Steel-it" paint. It's an rust stopper, oxygen barrier, weatherproof, weldable and you can touch it up with a spray can of the same paint. I am rebuilding my jeep frame and full roll cage and painting everything I can with it. I have used it before it great and perfect for offroad. It holds up VERY well and easy to maintain.
Too late now but tnt does talk about tacking angle iron to the frame to keep it together when you cut the cross member. They talk about it on their you tube channel. That's where I found out that my steering box sucks.
