Reply to "Backfire thru Carb and popping out the Exhaust"

Hi., Well I just went through the exact same thing you are describing. I replaced my dist. with a MSD and a new Holley carb. I also had backfire pops and compression coming back up the carb. If it backfires too much back through the carb you may blow a power valve and will have to replace it utherwise gas will just keep pouring into the cylinders.! Also if you have any kind of header leaks the cold air hitting the valves causes a "pop". Also the stock exhaust headers are way too small. Thus the motor can't breath enough which causes backpressure. I put on a set of aftermarket headers from a vendor in California for $200..(which bolt right up to the stock intermediate pipes) and new gaskets and my problem was solved! I also put on larger intermediate pipes and used the stock mufflers. With the MSD and an aluminum intake with a Holley carb, the new headers and larger pipes... really helped the motor breath better and the car runs great. No backfire or compression problems.