injectors - going from 550's to 680's... Advice

[TheClaw]

Currently I have 550's and they're maxed out..

Running a 255 pump, S-AFC, 20psi boost, etc.

My question - I am getting 680's today. Am I ok to just throw them in and lean it linearly down the line just a bit? Or will the tune change extensively? Will I need to spend a lot of time re-tuning? or should it be pretty close to the 550's?

Any help or direction is greatly appreciated.
Thanks guys

 

[daren_p]

To get you up & running, just leaning it out the same amount across the board will get you in the general area. To get the best performance, you should retune it though as different sized injectors are usually slightly different, such as the amount of deadtime.