I agree you're not going to have to worry about it blowing out. If your tires have good tread then run them. For a good overall tire I highly recommend the maxxis Bighorn. I feel it's one of the best overall tires you can get if you arent doing much mudding. The only thing you might want to check is your rim size. I believe the 420 had 11" rims. It's harder to find tires for them and the selection usually isnt as good so you might would consider some pull offs with 12s or just buying some 12 rims.