URGENT!!! HSV cat pipe length difference please help!!!

[W45H1NGT0N]

Hey everyone,
I need some help, I have bought a set of HSV VX headers (4 into 1's) and not sure if ill need to change the length of the cat pipes, does anyone know what the difference in cat pipe lengths is between a HSV VX (hsv headers 4 into 1's) and a VY SS (Stock cast iron headers)

I need this info as im swappig them over myself cos i dont wanna be ripped off by an exhaust shop.
So any help would be greatly appreciated.

Cheers

[colgf]

I am nearly certain you will have to change the length of the pipe from the joint with the extractors to the cat on both sides , also the joint flanges are different types , one side will be a flat flange with 2 bolts & the extractor could be a round ball joint type flange. Depends on the HSV model the extractors are coming from??? Wait till you get them & you will soon see whats needed. You may fluke it but I doubt it.....

[W45H1NGT0N]

I'm pretty sure I got the extractors with the round ball joint type which is the same as the standard headers, i just need to know (by how much) i need to shorten/lengthen the cat pipes