i was wondering in the 1977 gc210 master brake booster is the same for the 240z or 280z? the model i have has disc brakes in the front and drums in the rear.

What is the part number on it?

need a visual to match it up. is it small, med. or large in diameter. and does it use a spacer and have long studs to mount, etc.

Does the gc210 have a 3/4 or 15/16 stamping on it?

Maybe you need one of these:

http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=200030629436