I'm in the middle of doing and 0411 swap in my 99 OBS 383/4L80E Tahoe build and I know that everyone likes to use the Express Van Cal as a starting point which I've downloaded but after reading i would need 2 credits to load it into a junkyard pcm then another 2 credits to be able to edit the calibration. Is there any way to use the current ls calibration to run the l31 vortec motor? I've read the Efi connection 24x converion articles and book so I know all of the sensor calibrations are the same but the firing order is different and the ls's use coil on plug? Reason I aski is that I really need my truck running and I have only 2 credits left amd with the holidas I dont have the funds to buy more.credits anytime soon