Yeah, it's not a huge difference, but certainly worth looking at if you can get them cheap.
OK, so next question would be what air cleaners?!
I have the K&N's but these are no good with my ram tubes, so I'd need smaller ram tubes. The other option would be sock filters.
The big thing with my car is it still sneezes a bit sometimes out the carbies when it's cold so I don't want to set filters on fire or burn big holes in them everytime I start the car, so something a little resilient would be good.
What would be your recommendation there Peter, keep the K&N's or go with something like a sock filter, and then what brand? Should you oil them or not (I'm thinking oiling will kill performance, but increase filter life)?
To be honest, I'm thinking keep the K&N's and go with like a 25mm ram tube. The manifold on the zed is super long and the long ram tubes almost hit the strut tower, much like Scoota's pics there and I wouldn't mind some more top end in the car, it falls off pretty steeply at around 6500rpm, but that is likely just the cam restricting things.