84 K10 is still gutless after cam heads intake

[CentipedePerformance]

So I bought an '84 k10 as a daily a while back. It had a GM Goodwrench 350 put in it 4 years ago, and was otherwise stock. I rebuilt the 700r4 with the better pump, planetaries, a shift kit and mild converter. I then put port matched TBI heads on, an Edelbrock Performer intake, Edelbrock 650 cfm carb, with a Melling MTC-1 cam, Tri-Y headers, 2.5" mandrel bent y pipe to 3" single in/out Flowmaster. Distributor has an Accel ICU, Accel coil, timing at 37* with full advance coming in at around 3000 rpm. Vacuum advance is hooked up to manifold vacuum. There is no longer any emissions junk on the truck. No smog pump, no cat, no egr, and it has the hard parts for a solid running motor. It has way more just off idle than it used to, but is still gutless. I am hard pressed to feel a difference between 1/2 and full throttle. What could I be missing? Gears maybe? Its got a 4" lift with 33's and what I would guess are stock gears.