Replacing rockers and partial floor......uh oh.....Help!!!!

[Slik66]

So, from advice from a few local people that have restored trucks, they said I didn't need to support the cab with cross bracing.

I replaced the inner and outer rocker and partial floor where your feet go on the drivers side no problem. Everything went good.
Moved to passenger side to do the same and everything is off bad. The gaps are huge, 1/2" or more front and back, and the rocker had to be cut in half and called about 5/8" for the door to close.
I cut the rocker and set it in but I got to thinking, I shouldn't have to cut the rocker and something more serious is wrong. I feel like the front post has sprung forward but have no way to verify that.

Any help or tips to measure or figure this out is much appreciated!