I have a 99Z28 with the below mods.
"Stock 99 LS1 intake manifold
Stage II Ported 241 Castings
28.8lb Injectors "Maxed out"
1 3/4 Mid-lengths and a bunch of small items.
Custom Tune
437rwhp and 398rwtq is what it dynoed a month ago.

I was going to add the the below items and I was wondering what I should pick up power wise.

85mm Polished T/B
85mm Professional Products intake manifold. "Block off EGR"
42lb Injectors
New custom Dyno Tune.

Thanks for any input..