Planning 402 build - help!!!

[GAc10boy]

So, I planned to keep my L6 intact in my '71 but after getting it up and running, I've decided it isn't going to satisfy my every want and desire. I'm looking to build a nice, streetable period correct 402 to match my th350, 3.73 gear, hei equipped swb stepper.

I've found a '71 402 w/ #820 heads and stock from there. Complete motor, pulleys, carb, intake & exhaust manifolds, etc.

After researching here and the chevelle forum, my plans are this:

Keep the #820 heads and stock pistons , etc.
Put the Lunati 60202 cam, lifter, and valve spring kit
Edelbrock Performer 2.0 intake
Edelbrock Performer performer 750 cfm carb
Sanderson small tube headers (I think they're 1 3/4 tubes)
2 1/2 inch Flowmaster 50 exhaust


Questions: should I upgrade to new rocker arms? How much hp should this make at flywheel? Shooting for 375-400 hp at the flywheel.

Thanks!