main thoughts with 125 shot are...... 1 step colder plugs gapped a little tighter. Retard timing about 2 degrees across the board with Predator. Run vehicle low on gas to track and put some 108-110 in (2 gallons) for a safety net and keep knock retard out. You will be utterly amazed at how the HEMIs respond to the juice. Good luck, and keep us posted. You should pick up close to a second depending on vehicle and how quick you are now.