firemn131

I have two sets of 87 S4 fuel rails and intakes.
I have marked them accordingly with the matched intakes that they came off of.

My original set is off of the earlier car that has the intake without the center ridges, and uses rubber rail mounting studs.
So I understand that;
* Early intakes use rubber mount studs that screw directly into intake for the rails,
* Later intakes used aluminum spacers.
There are measurable differences on the different intake mounting spots.

What I cant find is a difference in any way on the intake rails.

Are they interchangeable as long as the correct mounting hardware (spacers or rubber mounts) is used.
If different, where do I measure a difference?

Is there any preference for which intake/rail combination to use, early or later?


Thanks as always.


If there are differences in the actual rails, can someone point me in the right direction?