I want to thank all of the folks at V-Belt Guys for working to resolve issues I had encountered in acquiring the correct length belt for my dual pulley alternator in my 1958 Corvette with a 327cid/430hp motor. After reworking the engine, the 2 belts needed to be 1/2" longer than the previous Gates 7550 belts. Numerically, a Dayco 15555 0r Napa 25-15555 should have met that requirement. Unfortunately, after working with Bobbi (sp.) at V-Belt Guys, 3 sets of belts were sent to me as the solution. The first set, 2 @ D&D 15555, was actually about 1/2" shorter than the Gates 7550 belts. The second set, 2 @ PIX E'tra 15560, was the exact same length as the Gates 7550 belts. The third set, 2 @ D&D 15565, was (in fact) 1/2" longer than the Gates 7550 belts and worked perfectly. I was able to just work them on the dual pulleys and tighten them within the restricted range of adjustment. Bobbi told me to not return the previously sent belts. I was upset that I could not convince her to have me return them, even with me willing to pay shipping. So, now I have v-belt wall art. Please extend a warm and heartfelt thanks to all the folks at your operation. I will continue to use your products as I am in the business of repairing and restoring "old iron:, American classic cars. Been in the auto repair business for 54 years, going strong, and always happy to find a new resource for parts. Best to all, Chris