My 9.5" Precision 4,000 stall convertor flashes to 4800 - but I'm blowing thru it the whole pass. I'm only dropping 700 rpm on each shift - so it shifts at 6500 and shift recovery is at 5800 - so it's not ever even coming close to 1:1. I was thinking about trying my 11" again, but not interested in all that labor at the moment. LOL