This is well worth the cost. You need to buy new bolts when your do anything with the head anyway so why not buy a stud kit. The kit is really nice, very well built and worked well. The instructions in the kit are easy to follow. I would recommend this product.
I am running a 2.25" exhaust with an 18" magnaflow resonator and an 18" magnaflow muffler with a test pipeit still had quire a bit of raspy sound. I installed this resonator in the test pipe and it made a huge difference. All raspyness is gone and the overall exhaust is quieter.