I'm using a new 250-type of balancer, modified to install on a 235/261 by Steve of BUFFALO ENTERPRISES, 25625 Dahl Road, Arlington, WA, 98223
(360) 652-7684, Steve does not have a website; you need to call him.

I also have drilled and tapped the crankshaft to use a SBC bolt to draw on the pulley.

Hoyt