Alphaman19

It most possibly works in other models (GS300 as well) but I can confirm that it's a direct replacement for the '98 GS400 since I just installed it into mine this past weekend.

I got the bmc off of a wrecked 2003 SC430 with only 80k on it. I took it off myself so I know it's what it is as opposed to buying one online and hoping it's what they say it is. I kept/used my original abs computer (located next to the brake pedal).

Dropped it in and after a good bleed, the brakes felt much firmer than with the original abs unit.

Since it's not only a better unit but less expensive also (dunno why - it looks exactly any other 2nd gen master cylinder), I'd strongly recommend going this route if you're in need of a bmc.