no hp differences
belanger is coated and comes with mids, and with or without cats, retail around 2k
billy boats stainless non coated, best welds in the biz, headers alone 2k, cat back $1400
both are great, depends on what you want honestly, BB is the best around
Lou makes killer sets affordably
both about the same hp and trq
both mike and lou are great guys, very helpful, knowledgable, need any help just holler