I picked up another guy's shortblock. It's a 1990 350 2 bolt block with a scat two piece 383 crank (3.75"). He claimed it was balanced, and there are some hole drilled in the crank throws, but all I got in the deal was a pioneer balancer. I figure it's the right one, because it's got a big weight screwed onto the back it it. What flywheel can I run with this. The previous one was from my forged crank 327, and has a weight (a lug nut actually) welded onto it. Do I just remove the lug nut, or can I buy an ext balanced flywheel?
Mike  

You're gonna need to get a 383 specific flywheel and then have it balanced to the crank and balancer by a machine shop. That's the best way to do it.