3970010 was a 2 or 4 bolt main block that came as either a 302, 327, or 350. HP ranged from 150-375. 33882 heads were the most common heads produced during the pollution controlled 70's. They have 76cc combustion chambers and 1.94/1.5 valves. The are prone to cracking. So, you've probably got a 150-165hp ls9 350 (GM rates them at 260 now). Nothing special, but it still has a little torque to it.