Paulie I looked into that option last year and they will take the HP and Torque up to the 360 model with the same torque. I also found a chip that is adjustable that claims up to 30% increase in HP and Torque adjusted to what the Trans will take. It is undetectable and doesn't void the warranty. I don't have to much warranty left so I just need to decide. I will definitely do something. I talked to several Allison reps and they all told me not to do it but when pushed "off the record " they said it wouldn't hurt the 2500 as long as I kept the GCVW in spec and I didn't hot rod it. Ya right a 40' MH hot rod.
Phil and Dianna
2011 Berkshire 390 RB