Yea, I did this mid last year and changed the engines on the 737. I’ll post a link where to find it.
EDIT: New engines on the 738
Simply editing the JSON file, you can decided which engine style you want. 100% backwards compatible too. the way I did it.
Thank you for your good explanation Now we can understand it better
Is it possible to have wings as an option for modding that has to be specified in the json so that it only effects load time if the texture is changed form the default.