Hey guys , new guy here. I have a 2003 reg cab 4.8 4l60e that I recently had a complete 2006 Cadillac escalade engine that I put in myself ... I got past the passlock crap and go it started ... It runs fine but won't downshift at 30mph or 60mph and I have it at the transmission shop and the guy says it's only getting 65% throttle when all the way Dow ! I'm using everything that the donor came with( motor accessories and wiring harness , computer even o2 sensors) the only thing I didn't use is the gas pedal for the motorized pedals ( obviously bc it won't fit mine bc I don't have that option) it's a stock 6.0 lq9 ... I'm lost,any help would be great guys ... Thanks