I have a 6157e turbo. Currently the stall is 3200-3500. I thought I requested 3000-3200 when the trans got rebuilt but that ship has sailed. Transmission builder is recommending 2500-2800. Is there some mathematical equation that can get this dead on? Also, which would give me better gas mileage, the 2500-2800 or something higher? How can I decide which one to get? How much should it cost to get it restalled, parts and labor to remove and reinstall the transmission included? Can this be done while I wait? Thanks.