HT4100 4.1, 4.5, 4.9 Discussion, Changing Final Drive ratio/ ECM tuning in Cadillac Engine Discussion; So I want to change the final drive ratio in my 4T60-E to either 3.06:1 or 3.43:1 (haven't decided yet) ...
Automobile(s): 1998 Seville STS / 2013 Chevrolet Impala
Changing Final Drive ratio/ ECM tuning
So I want to change the final drive ratio in my 4T60-E to either 3.06:1 or 3.43:1 (haven't decided yet) and I know what I need to get it done, but I wondered if the car would need ECM tuning afterward. I'm assuming the shift points on the transmission would need to be changed, but I'm not sure. Does anyone know?
Also, where would I get ECM tuning done for this car? I know I can buy the software myself, but I don't really want to foot the bill for it at the moment.