follow up: i've been using the tfs intake setup with the one inch phenolic spacer, and recently i bought new trick flow valve covers. with the one incha spacer i can take my valve covers off without having to mess with the intake! that's a huge timesaver. also i noticed that with the spacer the upper intake stays much cooler. i use a zex nitrous kit sometimes, and just out of curiosity i tried it a few times without the spacer. i was very surprised at the difference. with the spacer it hits much harder and you get much more of a sotp feel. if you're going to use laughing gas, i highly recommend the spacer! i believe the difference i saw was because of two main reasons: #1 the air intake charge has a little more velocity due to the increased runner length, #2 the air intake charge is much cooler, thus causing a better detonation in the combustion chamber, which is a good thing. if you have a cowl hood that will clear the soacer, i say go for it man.