MSD Atomic EFI

Absolutely the best improvement for my 5.7. It was built in 2007 when no parts were available and I chose to put a carb on it. This engine does not like a carb, driveability issues were always a problem. The Atomic has been fantastic on it. Definitely put it with the return line and a quality regulator. I put the system on and found that the pump would get hot and quit. No longer a concern after the return system installed. MSD has a Pontiac at over 600 horses that runs the Atomic system, it will handle about anything you can put it on. It will not sit on the starting line on a rev limiter though. There is no provision to keep the system from learning the tune while it is on the rev limit from another component.