I agree. Especially on the rear end, when it goes bang it'll likely take the sprag with it, now you're pulling a trans too. Swingers have a weird wheel lip, maybe a 275/60 with the perfect offset rim.
with the springs moved in and the out lip rolled i can run a 275/60/15 et street radial or a ET street radial pro with a weld drag light that is 15x8 with 4.5 inches of back spacing. the tire is close to the front 1/4 panel but it will work. i did end up moving my rear back 1-1/4 inches for a bigger tire but have not tired one yet. i have been 10.49 at 125 in the 1/4 so far with my 3520 pound 73 big block dart. best 60 foot has only been a 1.48 but that was with a miss matched converter. i have the mopar 002/003 super stock springs, cheep dodge ramcharger shocks in back. stock front end with summit brand 90/10 shocks in the front. best of luck on your car. mopar65