Restrictive air filters?

I run the 83mm version of that K&N with ramtubes inside them.  I think the ramtubes are about 35mm long so plenty of room.

I have no personal experience with them but I have read in many threads and sources that foam filter socks are bad for airflow into the carbies.  Upsets it too much.

great info. Thanks

Socks are a huge no no!  Not only do they flow crap, but the way they are mounted upsets the effect on the ram tube.  Last Pinto I dyno'd dropped 8rwkw (yes, we double checked it, it was that much) when the socks were fitted, and I've done heaps of other engines with the same sort of effect.
 
K&N's are good with a ram tube underneath.  I recommend the entry of the tube to be a MINIMUM of 40-50mm away from the filter top.  The other method that works well is the box type arrangement with tubes underneath, as long as you can feed it enough air. 
 
Cheers
Woz

ratta tat tat

looks like i'll be needing something like this then

 
Whats the longest air filter you can fit in? (or thickest in other words)
 
Woz

ratta tat tat

I had a redline to start with @ 80mm. It was tapping the side of engine bay so i bought the 50mm wide K&N.

 
I'd like to see a longer ram tube and longer filter.  If you can play around with the engine mounts to stop it tapping then I'd try the 80mm item with about a 30-40mm tube underneath.
 
Woz