I am fitting a 2.0l xetec to my Robin Hood and i am now at the stage of choosing a manifold, i am using my DHLA 40s therfore need one to suit, after finding some i now have a choice "Long or Short".
The long one is 100mm flange to flange
The short one is 69mm flange to flange
Which one should i go for?, will it make any difference eg more power?

As long as you can get to fit. It does make a differance with weber dcoe's

So i should go for the long one?
What sort of difference will it make oppose to the short one. How does it make a difference?
Cheers

As far as I understand it, the shorter the intake length,the higher up in the rev. range the max power will be.
Longer intake will give opposite effect, but will also give better low down torque.