well to start off, good afternoon. the car: 1974 xr7. engine: 1971 302, standard bore and stroke. performer rpm heads, performer 289 intake, 750 holly dual feed carb, crane cam and lifter set, noisy gear timing set, 1.6 roller rocker and tall valve covers. so i guess it would be mildly modified? anyway now to the problem: the intake was the last installed part and all went well. set the timing to 6deg adv. to start and set the carb back to stock settings. but the issue is i have throttle response at idle(550rpm) in park, the engine hickups around 1100rpm then runs correct past 1200rpm. in drive idle rpm is around 500 but has absolutly 0 power, throttle response or brakes. what could be the cause i dont have enough experience in dealing with this to trouble shoot. any help would be better than what i have now thanks.