The77novaguy

Hey yall, so I got a 2011 gmc 2500 6.0 with 823 heads, pulled motor dbw pedal and ecu. Found the harness I ordered was for a e38 style ecu. Put a e38 in the 77 nova the motor is sitting in. Wired everything up got a base map tune. Car starts and idles.. throttle on hp tuners reads 88% with your foot off the pedal completely and drops to around 15% at WOT. Looks like the throttle body is trying to run backwards. Is there a way to reverse polarity or swap the 5v reference to a different pin location to get the throttle body to run the other way? Any help or insight is greatly appreciated! Thanks in advance!!