Skinny springs 1972 Stepside longbed
 

I know I have read on here somewhere smaller diameter springs to use on the rear to provide clearance for large width tires, I have searched and cant find the posts. I have 29 x 15.5 x 15 Hoosier Pro Streets, I have tubbed the wells but I am not going to be able to use the stock springs due to their diameter. Any ideas on what springs I need to run?