if you are running stock heads you will be lucky to make 300. vortec or aftermarket heads could make more. you didnt say the duration of the cam.

 

I built a old school 327 bored .06 over around a 337, with 4+ cc dome pistons 11.6 compression, old school 58cc z28 heads and intake, 750 holley, with the corvette 327 solid roller cam. put down 372rwhp and 384rwtq through a 4 speed on one of our 67 camaros.

Your motor has more cubes but 1 point lower compression and idk about your cam or heads, but I bet you would put down +/- 350