My hemi would throw or break belts until I changed them over to Dayco Top Cog belts. No problems in over 3 years up to 7500 rpms. They run them on Nascar motors. I think you can get them at advance auto. I bought a bunch off Amazon that were extras from a race team and they only cost about $2.99 each plus 1 shipping charge of ten bucks. Cured my problem.