I'd definitely recommend bigger injectors than 550's. I was at 457 on 660's. I HAD to upgrade from the 550's once I got to about 400 whp and I was at 9.5:1 CR.

I was using the Greddy Type24 FMIC on my Garrett T3/T04E 57 trim .60 A/R.

The ACT XTR6 I was running was tough for daily driving, but definitely held the hp (torque actually).

Be sure to get the Walbro 255 HP FP. Not the LP.

Any thoughts on upgraded axles? I used OEM replacements from NAPA, which worked well as long as you preload them off the line. I snapped a few dropping the clutch before I knew about preloading. I also didn't have LSD and only ran drag radials, never slicks.

I'd also recommend a FPR (not the B&M modifier) so that you can change your static pressure if needed.

Don't use the skunk2 manifold either. Go with JG or FullRace. The runners on these are shorter and fatter. They allow for much better flow.

I'd also recommend some ITR cams and adjustable gears. I gained 9whp just off of adjusting the intake cam. The ITR cams were also a really great upgrade from the GSR's with boost.

That's all I can think of at the moment.