Hey guys, I'm in the process of modding my TBI unit in my 4.3
have a spare one laying around so I figured why not.
have a 14" open K&N
ground down the throttle blade rods (carefully)
and took the ridges down around the bores..

what kind of gains are you guys seeing from doing this mod?

 

You probably won't see any gains on a an otherwise stock motor. There are reported 4% flow gains but I have not seen any real testing evidence. The key is to unshroud the base of the TBI unit. Removing the casting lip along with using an injecor spacer clears the space around the injector pod which allows more air to be drawn in. Most people don't see any track improvements but will see a slight egde when their heads and cam set-up is on the edge of needing a 2" unit.

 

It does have a few mods
4.3 .030 over w/ hypereutectic pistons.
Ported Stock heads - 1.94/1.6 valves.
1.5 roller tipped rockers
Comp Cam 266HR - .500\.500 gross lift - 266/270 adv duration.
2.25 dynomax ultraflo exhuast.

just the basics

I was going to go with a Holley unit but I've heard a lot of mixed things about those. I dont know if its neccessary for that much flow on this engine. Havent had my chip tuned yet so it runs pretty rich on the stock tbi unit.