are you talking a 6.71 blower or ??? seems like a lot of trouble building an intake that is going to have problems getting to the bolts,,,a back fires dont always happen at light throttle,,the blow off valve can help from gernading a motor if you build to much pressure,,and if for soem reason your motor leans out under load it wil back fire like mad and blow that valve open,,,saving your blower and carbs from lift off,,ask me i know,,,,,,,pics when you get it sounds intresting