Remember your big cam is going to bring boost down...

 

Maybe your D1 has P1 or Powerdyne guts in it.

 

There is another member on here with a silverado ss with a big cam heads exhaust, basically all the same mods and is getting 18 psi with the 3.6" pulley at 6800 rpm. I saw 10 at 6200 with the old set up and the 3.85" pulley

 

I know the intercooler is a restriction. Last weekend I blew the pre intercooler pipes apart. And the had the band clamps on them. Not the crappy warm gear ones. I'm going to get a 1/8 barb to 1/8npt threes and install it in a spare coupler and install it just before the intercooler. I'm going to hook my boost pressure gauge to it the. To a test run and see wha my boost gauge says.

 

Are your intercooler pipes bead rolled?

 

Yes, the ends are rolled.