Hello guys I'm new to this diesel world, hopefully someone will be able to help. so I'm having issues what I think my transmission is taking long to switch I just got my truck back from the mechanic that deleted my truck and installed my mm3 from drd. I have 33x12.5r20 when I go to tire diameter it says 33.20 I want to know if that's correct or what # do I put in? Any help will be highly appreciated thanks