I have a bored out 454 tbi throttle body. It has a claimed flow rate of 750cfm. Each bore is now 2 Inches. The lower intake manifold is a stock 4.3 manifold but was glass bead blasted and the intake bores were matched to the throttle body. They are an exact match, both 2inch. Stock, the 4.3 tbi manifold had 1 3/4 inch bores. With these two items you also get Felpro lower intake manifold gaskets, Felpro throttle body gasket, and a Felpro EGR gasket. Every thing you need to install this, short of all the sensors. Would be a good addition for anyone with a pre 96 tbi 4.3. I am asking 450$OBO