They start to bulge a bit because the middle is held by the wheel width. You can put just about as wide a tire on as you want, but they won't lay flat and will look odd. (and wear fast)
Also, stay clear of Coker. Go to Diamondback. They have redline radial T/A's. If you don't need them right away, they generally have a sale around the first of the year.
I used to be indecisive. Now I'm not sure. I feel like I am diagonally parked in a parallel universe. 1968 400 convertible (Scarlet) 1976 T/A - 455 SE (No Burt) 1968 400 coupe - R/A clone (Blue Pearl) (for sale) 1968 350 - 4 speed 'vert - 400 clone (the Beast!) 1968 350 convertible - Wife's car now- 400 clone (Aleutian Blue) (Blue Angel) 2008 Durango - DD 2008 GXP - New one from NH is AWESOME! 2017 Durango Citadel - Modern is nice! HEMI is amazing! 1998 Silverado Z71 - Father-daughter project 1967 326 convertible - Sold 1980 T/A SE Bandit - Sold