So I purchased an OTA track bar kit from CavFab and I cut off the passenger side UCA amount in order to fit the track bar bracket. I’m currently running a RC long arm kit and I was wondering if it was possible to just remove the upper arm on the passenger side to make it a “3 link” kit or will I need to purchase a true 3 link kit? I’ve heard that the geometry will be off but I just wanted to make sure before I spend $600+ on a 3 link.

You will find that one upper bushing will not last more than a week. They are not strong enough. I tried that, but went to a true three link later, Much better

I agree it's not strong enough, but it'll be fine overall. Same crap design that IRO used with their Critical Patch Y-link setup. I would say if you're going to run it like that get yourself a Currie upper bushing that uses a johnny joint and a beefier bolt. Last you want to do is take it off road and have the bolt snap on you.