I dont really care about one on one engine data, its the total thrust I want. What I did was copy the folder and renaming it to CS_727-100_sitm. Then I delete the texture.sitm in the regular 727-100 folder and removing it in the CFG. And the oposite in the other one.
It worked for me, the plane was there and everything was normal.

As to engine data and fuel burn, I did put the thrustscalar up a bit and the fulflow down. You have to keep in mind that this is the engines that was later fitted to the MDs, so to me that indicates that it have to have a significant more thrust than the regular 727.

I still havent found any hard numbers for the enginedata so I can calculate it. The math to me is simple when the numbers are there. The thrust and fuel burn on a regular 727 is 100% and go from there...

I will report back too on how it works.  :)