New dually owner in bama

Just got my hands on a 99 7.4 dually it's lowered new paint looking to do some motor upgrades headers tune cold air and info would be a huge help I've got a set of long tube headers off a 87 2500 don't know if they will fit any advise would b a huge help just looking for more power don't care about mpg lol

Since it seems these threads dont get any replys! I will cuz im new also! Hows it going!? Love your dually! Can't really say much about your questions! Tho I would think they would or should work if they came off a 454!? Were they both 2x4s?

clean dually

only difference might be the port shape seeing as the 99 is a vortec motor?