I "think" the DOT approval means it has a few grooves/sipes cut into the tread. So technically they're "legal" It doesnt mean they're safe on wet roads at speed (highway) Kinda sorta the same thing as all season tires that are near bald.
I also noticed most cars from the late 60's to early 70's with small and big block at the track run MT Drag Radialsp
I use the MTDR's this is my 2nd set, they do very well not much rubber gets on the car. I run a 373 gear and I can tell you I barely hit 5 grand in the traps. I have the 2004 trans and thinking of going to a 410 gear. In my video with the nitrous they spin very little off the line. The also do not need a big burn out to hook. You made the right choice but can get a little hairy if you get caught in the rain and are about 1/2 worn lol.
