Back in the day, I arbitrarily called the Galaxy-class starship nacelles LN-100s.
Given the long stretch from TMP to TNG, that might crowd the nomenclature to the point of being incredible. My whole theory on warp drive evolution was that linear warp drive nacelles (like those of the TMP refit Enterprise, Reliant, Grissom, etc.) were the Federation's way of playing catch-up with the newer, svelte linear warp technology (linear means "fourth power" warp drive, distinguishing it from the cruder "third power" tubular circumferential nacelles) used by the Klingons. A linear-warp-driven starship traveling at Warp 4 would outrun a circumferential warp-driven vessel flying at Warp 6. Hence, during "Elaan of Troyus", when Spock said "their speed is better than Warp 6," it was because the Klingon attack cruiser was operating at Linear Warp 4. And when Spock finally got the refit Enterprise's new engines to work properly, Kirk ordered the ship to Linear Warp 7, it would've been seven times faster than traditional Circumferential Warp 7.
I'm assuming that the nacelles on the refit Enterprise, Reliant, Grissom, Excelsior and all subsequent starships classes clear through TNG and DS9 and even VOY (transwarp/slipstream not withstanding) were all evolutions of linear warp drive. So perhaps the Galaxy's uber-big nacelles should be called LN-500s, or LN-5000s or somesuch.