B&M Question..

FIRST do you have the correct shift lever and cable mount? The BM shifter (as well as the Cheetah) both use special transmission levers proprietary to those shifters. The BM lever is very short, and I can see why it might be difficult to move with your fingers.

You have the correct destructions? You can download 'em

Some / all BM shifters have a stop that might need to be installed to allow/ disallow further movement for GM shift patterns.

I Don't think I set mine up strictly by the destructions----I set mine up by "feeling" the shifter in first / neutral (mine's reverse pattern) to be sure the "click" of the trans lever "feel" matched the gates in the shifter.

Then I checked park to be sure the neutral safety switch "made," and adjusted a turn or two on the cable end to compensate that.

There's been discussion that the trans shaft/ inner comb can generate "it's own" internal play