Do I need to use the phenolic spacer with the trick flow intake. It does not come with the kit and which thickness? The part number i was looking at is TFS-51520008. 1" thick.
i use the 1 inch thich spacer with my trick flow street intake and im not sure how much it helped i didnt do a b4 and after dyno.....but from what i hear its helps improve low end torque, which is what i wanted......b/c it lengthens the intake runners....but im pretty sure a stock hood wont shut either with the 1 inch spacer...but i heard the 3/4 spacer will work if you can move hose for the ac that usually sits on the itnake
i use the 1 inch spacer and i didn't see any immediate benefits, but it is a very handy thing to have when you add more mods. for instance i am going from stock rockers to 1.7 roller rockers with tall trick flow valve coves, and i won't have any clearance issues at all. i've even seen people tap and drill the spacers and add threaded barb fittings for running laughing gas or as a gauge port for an intake vac/boost gauge.
I think it is supposed to help keep the upper intake cooler as well as increasing the runner lengths. I don't think the stock hood will fit with it, but a cowl hood will.
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.