Cummins 275 sound mod for the Peterbilt 351

Hi all,
i have made a sound mod for the very very good Pet 351. This is a Cummins 275. I did search for informations about those engines (specs) to edit the .sii engines files, but it's hard to find and there's so many versions. 3
Also, my friend JujuQcTrucker updated his CAT 3406 sound mod which I include in this mod.