We got a guy here in UK runs a street/strip Demon in our NSS brkt class with a mild 416, has stock 340/360 J heads just cleaned up, probably not even 10:1CR, a mild hyd.flat tappet cam (unkown spec) it only pulls to around 5600. An Airgap intake and a 750DP, ran 11.6>7's with 3.55's and it has a 3500 stall converter, now runs 11.50's with 3.91's@115mph best, the car went slower with 4.10's. The motor makes 410fwhp. That will give you an idea of what is possible with those heads and a mild type hyd. cam.

Plenty of choices out there for ally heads, Speedmasters from what I've read on "A bodies only" have some issues, depends on how much work you can do to check/fix to make them right, only bolt on head is the TF190. I would stay with iron heads for a 95% street car to keep the heat in the c/chamber, your 2800 stall needs a relatively mild cam, prob around 230@.050 or so?. I've only run 340's/440 stock stroke motors so giving specs for your type combo is not in my thought process unless you wanted to make well over 500hp and rev it to 7k with a 5k stall.