A couple thoughts.
There is quite a debate over ST vs. LT tires. Read and make your own decision on that. I stuck with Maxxis ST tires. So far I am quite happy.
Old date code and cracks would argue for replacement.
In any case, get a good TPMS (tire pressure monitoring system). I use TST (truck systems technology). That alone brings some peace of mind. I had it for 2 or 3 years and nothing ever happened. Then twice in a month, the alarm went off and I was able to stop BEFORE hundreds of $ damage was done. Then I bought 4 Maxxis.
Good luck.