just rebuilt a 83 231 cylinder pressure is 125 on all cylinder,s, I have spark at all cylinders and it runs but the left bank has poor power i.e. when you pull plugwire on the right engine idle drops 200-300 rpm when you pull one on the left it is hardly detectable ,it dosent matter what wire its all the same on the side .any ideas??

If your compression is up, my first thoughts would be in your ignition. Maybe your cap and/or wires?

Does that have a distributor? Or does it have the 3 coils (like the Grand Nationals)?

The 3-coil system has a "waste spark" thing that might be goofed up.

-Bob C.