I have a Sniper TBI & dist. on a sbc 383, 9.4 comp, 227@.050, 530 lift, .373 rear, m21/cr, for street use. Timing & AFR can be infinitely programmed per rpm, map/kpa On my 2nd tune still have loss of pull at any type of stomp throttle situation, like a low pump shot, but that has been increased. Its sounds & feels like its popping out exhaust when it happens. Not a backfire more of a base tone (quiet exhaust), but not as bad if I ease throttle. 17 start/static, 38 cruise, 36 wot. AFR 13.3 cruise, 12.2 wot.