This harness allows for a 6l80/90 to be put behind a GMPP crate engine and harness. Tap shift is made simple by provided up/down switch (we also include instructions on how to source your own switch if you prefer). HPtuners is required for install/tuning. Full diagnostic and tuning supported by most tools like HP Tuners – making tuning a breeze vs a separate aftermarket controller! Seamless operation with your GMPP harness.
NOTE: Most wiring harnesses are taking 1-2 weeks to process/ship due to a high volume of orders. If you need immediate shipping please call to confirm availability. To ensure your place in line, please place an order as we ship paid orders first before posting back in stock notices. We can refund at any time.