AMS stated that if your going to run the stock ecu then go with the jun 264s because you will have a very hard time getting the jun 272s to idle. In addition on the jun website they stated that the 264s can be ran with the stock ecu.

Anyhow, back on subject what I was looking for is if the jun 264s would make better power and better spoolup than hks 280s on a 35r with a custom flashed ecu.