I brought my filter into home depot to make sure itd fit into the cone too by the way. I bought the wrong size pvc just by guessing. The tb is around 3-3.25" and the maf is 3.25" I think I read.I drilled a hole in the coupler and put the vaccum or pcv valve w.e it is n put it between the tb n maf..you can see in the first pic