Dyno Vs.Drag Strip Testing

I saw that converter problem too. We had a racer at my local track with a nicely built early fifties chevy with a small inch sprint car motor that he was spinning to eight grand. Problem was , it left at eight grand and stayed there the whole way down the track. You literally couldnt hear an rpm change at the gear change! I think everybody at the track that tried to help him told him his converter was not just wrong, but completely garbage too.
When he finally changed it, i think his car picked up something like six tenths in the eighth.