Not more than 329hp. On a good day. and no torque.
The 882 heads along with the 462624 heads are the worst of the worst SBC heads.
You will see a huge increase in performance just by getting better cylinder heads.
+80 hp 1 whole sec et reduction, big MPH increase in the 1/4 mile after ditching these dogs.
Until you upgrade the 882 heads this motor is going to be a disappointment.