i tried searching but

[oatsk5]

so i just put a set of headers on my 400 sbc and know it pops through the exhaust and has a big lack of power the headers are off another truck i had it really agrivating as the ruck needed a tune up and i did that at the same time and i verified the wires and what not any help would be nice

 

[bandit4369]

I'd put my money on the tune up, not the headers unless, you had an O2 sensor before and you didn't hook it back up when you changed to the headers.

 

[81K5GUY]

make sure you got the right plugs in it

 

[big dan]

didnt cross wires did you? when I put new wires on mine recently I got a little careless and switched up the number one and two cylinders so the wire for number one was on number two. it sounded like a gun going off each time one of those two cylinders hit.

 

[theperfectgarage]

Kinda sounds like a misplaced plug wire. Also make sure no collector leaks, that can cause backfireing ( especially when you let off the throttle ).

Fresh air at the collector area re-ignites unburnt fuel in your exhaust and " pops".

 

[pauly383]

Of course you adjusted the timing and carb afterwards , right ? The engine can breathe better now , its going to run a little bit differently now , its scavenging the cylinders a lot better now .

 

[blazinzuk]

I vote for plug wires on wrong.