You may be surprised once the tune is good. If you just want to turn wrenches, do the swap. Otherwise, you'd probably be hard pressed to notice any significant difference between the 254 & 57h.

 

I'm confused as to where this 254 came in? They don't come in stock bikes.

I'd rather pay double to have a 57h over the 254e

 

57H on a 103? 100/120? That's a heck of a tune.

I put a 57H in my -13 RGU and Ed Dahir only got 92/109. Similar headers.
I put a 57H in my -12 CVO 110 and Dustin Werner got 103/111. Again, Cobra Power Port headers are nearly identical to the S&S duals.

 

The guys that tuned mine just took a 120st in a brand new 2015 RG that the dealer tuned and it came to them at, well let me show you the sheet. The OP is very pleased to say the least. J&B Performance can tune but again the 2-n-1 will bring the Tq on sooner.
The 1st sheet is after the tune but the 2nd sheet is the way it was delivered after the dealer tuned and said it was good.