I have a 1988 GMC C2500 350 TBI Vin K Truck with a 3:42 rear end and the 700R4 trans. I have the old EPROM (Hypertech) chip for a 4:10 setup which came with the truck new. Does anyone know where I can get/purchase a chip designed for the NEW Setup I have now 3:42 Gears? Im Stuck on 14 MPG and I just replaced the engine with an R/V cam . Thanks[/COLOR]

 

Download TunerPro and a $42 (1227747 ECU file) and some stock .BIN files. Download WINALDL and Build the cable. Buy a Moates Burn 1 prom burner, Moates G2 adapter, ZIF socket, 29C256 flash chips, and a spare ECM. Solder the G2 into place after removing the originol prom socket. Plug the ZIF into that. The chip goes into the ZIF. You take the factory chip and read it. Then you can make changes to the .BIN file. $200 if you have access to a good laptop!

Other than some small timing, VE, AE, TCC adjustments there is not really much to change from the gear swap. Just make sure your speedometer gears are calibrated right!