Acceptable converter slippage?
 

I think my converter may be slipping more than it should be. It is a B&M 3500 stall in my TH350.

Going through the traps at 111.611 mph the tach was at 5700rpm. I have 3.73 gears and I am running 28X13.5 ET Streets.

By the calculator on this site I shouldn't be near that rpm at that speed.

My calculations put it at 12.355%. I don't know what's acceptable but anything under 10% I feel is good. As a comparrison, my converter data for this year had 7% slippage. It's possible the tranny itself is slipping too.

29.9" tall tire
4.56 gears
crossing the finish line at 7150 rpm at just under 130 mph

Thanks Stephen, the B&M converter in there now is a low cost white box version. I have another 3500 stall here so I think I will swap them and see if that makes a difference.