Where on Earth can I find posts or rules about such a wonderful thing???!!!???
I saw expanded drive lists somewhere around here. And there's an article by Ken Pick over on freelancetraveller which describes a '77-'79ish campaign where they did something like that - ganged up drives to move big ships, allowed for missile bays and "bank lasers" and so forth. That sort of thing strikes me as valid Proto-Travellerism, especially if it's not overused and pretty much stays in the astropolitical realm of things.