Not a waxer
As has been said many times on both forums; the upper control arms are not a Factory Five specific part and can be assembled in various configurations depending on the application. The orientation that they are in when shipped from the vendor are not the proper configuration for our cars. It's up to the end used to do the "mix & match, flip & turn" of the components to wind up in the proper configuration. So, looking at your photo we can see that you have installed the ball joint in the correct direction however it is not seated:This is how the BJs are on the UCA. is it possible the rest of the assembly was upside down?
looking at the pics again, I think I did put the BJs on correctly. I think the rest of the assembly is upside down. It looks like the bolts should be coming in from above and the nuts should be on the bottom? I'll flip everything around and keep the BJs in the UCAs as shown. On a separate note, you can see that the BJ is not fully seated in the UCA. This is as tight as I can get it even using a bench top clamp. Any suggestions getting these last 2 threads to turn? Do I need to get a torch? I've read some other forums complaining of the stock BJs that come with the complete kit and recommended getting other ball joints, in which case I'll need a torch to remove the current ones.
You can't leave it like this and yeah, since you used the red thread locker it's probably going to be difficult to move without heat. Sorry Although some builders may feel otherwise---after having installed a bunch of them I've personally never had problems with the FFR supplied ball joints BUT (and this is a big but) you must remove the thick rust preventative coating from the threads before attempting to install them or they are likely to bind up much like yours did. Run them across a wire wheel to get get that stuff off and once you have them down to clean bare metal threads they'll turn in with very little effort and seat with a healthy "OOMPH".
As for spreading the tabs you can make a homebrewed tool with a section of threaded rod a few inches long, a couple of nuts and flat washers. The threaded rod goes through the holes in the tabs with nuts threaded on as shown here:
Turning the nuts opposite each other will spread the tabs. Easy peasey!