I'm going to replace my OEM catalytic converter with a Walker 16457 Ultra EX direct fit converter. I've given all of the fasteners a good shot of PB Blaster and will hit them again before the weekend comes. Hopefully, I won't break or need to cut any of the bolts. If I do cut or break one or more of the bolts, is it absolutely necessary to use identical bolts or will a different bolt/washer/nut combination suffice? I assume all the bolts need to do is pull the joint together. The replacement bolts from Honda are quite pricey. If I were to go to a hardware store to procure replacement bolts for this purpose, what specs would I want?