Is it something I should be concerned about? 3.4 left 4.2 right

 

I would say yes. Caster should be about positive 3 on both sides. It isn't Adjustable unless you shim radius Rods or get custom parts made or find offset bushings that fit.

Check the right side suspension arms and see if anything is bent.

 

If your caster is off than you more than likely have worn out radius rod bushing, bent LCA, or knuckle, and/or bad ball joints. I had a bent LCA that caused my caster to be out enough that the car turned completely different in each direction and was not noticeable holding the new control arm beside the bent one.

 

I recently changed the radius rod bushings all 4 of them. It seems they were pulled to far forward. maybe they will set it. the reason I changed them was because I hit a giant pot hold and it busted the nut off the radius rod and stripped the threads. I installed a new radius rod and all 4 bushings. Maybe when torqueing them down I pulled them to far forward.

 

If I remember correctly the bushings are different sizes and need to be installed in specific order/placement. That might be your issue.

2 are one size and other 2 are different. You probably have longer 2 on same side and shorter 2 on other.

 

I installed them right and made sure but maybe I'm blind. I'll check that though. If not I'm thinking shims or subframe shift

 

You can't always trust ppl doing alignments to use machines properly.

I went in for an alignment last week and when handed paper wondered why my caster was listed as 2.1 and 2.4. Went back today to get it re-adjusted from a different tech and readings were 2.8 this time.

Still think yours might be related to hitting pothole and bending something though.