Question about Headers for 07 4.7l flex fuel
#11
You would have to get them custom fabricated and you would have to relocate the catalytic converters and O2 sensors by moving them back.
#13
#15
It all really depends on what the original cast manifolds are like, on my 93 they are a log shape piece of poo! This style of header is the cheapest for the factory to make and is a reason to why they were commonly use, and I can only imagine that almost 20 years ago they didnt know as much about tuning exhaust as they do now.
Shorty style headers (similar to log style) are a step up from stock and will show minimal power gains the majority of the power gains showing up in the top end of your power curve which isnt good for any type of truck unless its being drag raced.
Long tube style (Full Length) are the best you can get for a truck as it will produce power increases in your low to mid range power curve which is what all trucks want (same reason why truck engines are cammed different).
Equal length runners dont really matter too much in this situation because there is little to no exhaust overlap, and no turbo charger so there is no need to make them equal length, all this does is space the exhaust pulses which would help combat harmoic resistance from resonance allowing a turbo charger to spool faster and such engines like a rotary which have high exhaust overlap to run better.
Hedman Hedders has some applications for the 4.7L as well
Non-Coated: 79570
HTC Coated: 79576
Shorty style headers (similar to log style) are a step up from stock and will show minimal power gains the majority of the power gains showing up in the top end of your power curve which isnt good for any type of truck unless its being drag raced.
Long tube style (Full Length) are the best you can get for a truck as it will produce power increases in your low to mid range power curve which is what all trucks want (same reason why truck engines are cammed different).
Equal length runners dont really matter too much in this situation because there is little to no exhaust overlap, and no turbo charger so there is no need to make them equal length, all this does is space the exhaust pulses which would help combat harmoic resistance from resonance allowing a turbo charger to spool faster and such engines like a rotary which have high exhaust overlap to run better.
Hedman Hedders has some applications for the 4.7L as well
Non-Coated: 79570
HTC Coated: 79576
#17
#18
#20
https://dodgeforum.com/forum/2nd-gen...pic-heavy.html