Somewhere in the 700's depending on the dyno/drivetrain.I think the compressor just dosent flow enough up high.Now if you use a small cam with no overlap that would help.I think that would be a waste of ci. though.Then again I am not clear on your goal here.

 

Stock manifold will run fine for you (408 with stock heads).

 

This. Going to a bigger turbine house will just change where the boost starts (and changes the exhaust pressure), but you'll still be running out of breath up top.

 

I think u misunderstood me or maybe I didn't say it right.By compressor I meant turbo as a whole.

 

Nevermind I see what you mean I still believe the turbo will be the most prominate restriction in that setup but yeah heads are going to come in at a close 2nd.

 

my goal is to have a DD with 700+rwhp on pump gas and have it spool good and pull hard ...

i'm not trying to have a 3800stall or it falling off at 5000rpm ether

i am willing to buy a 1.15ar (its divided) if it will "help"

 

I think you will be fine with the current turbo then.I promise you will get used to it then want more.Btw: what's this going in?

 

i have a 2000 RCSB full size w/ manual windows/locks i am pulling the 4.3L out and swapping
05 wiring harness and computer (6.0l/4l80e)
05 avalanche front end
05 interior

i know i will want more but i'm sure it will be easier to build the motor nig now and swap out turbo's later rather than build a forged 370 and want more cubes later

 

As I said in your other thread, that turbo will take you to 700ish, but no farther. Changing the exhaust housing won't change that.

 

i was asking if it would be better RPM wise not HP wise