The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - GM Performance ECU

LS short box · 01-06-2026, 10:43 PM

What trans are you going to use? Which LS engine?
On my auto LS swaps the tuner could tune the shift points as I liked.
I like and use Speartech or Howell harness and ecm for the base tune.
Nothing against PSI I'm sure they can help in the same way.

01-06-2026, 10:43 PM	#2
LS short box Registered User Join Date: Jun 2015 Location: Carlos MN Posts: 2,591	Re: GM Performance ECU - tunable for 33" tires? What trans are you going to use? Which LS engine? On my auto LS swaps the tuner could tune the shift points as I liked. I like and use Speartech or Howell harness and ecm for the base tune. Nothing against PSI I'm sure they can help in the same way.