Options for brake master cylinder

300ZX Master Cylinders

46010-30P01 Manufacture date 2/89 — 7/90 (17/16" NA Tokico)
46010-30P02 Manufacture date 7/89 — 7/90 (17/16" TT Tokico)
46010-30P02 Manufacture date 7/90 — 2/91 (17/16" NA & TT Tokico)
46010-30P10 Manufacture date 2/89 — 7/90 (15/16" NA Nabco non-ABS)
46010-30P21 Manufacture date 2/89 — 7/90 (17/16" NA Nabco)
46010-30P22 Manufacture date 7/89 — 7/90 (17/16" TT Nabco)
46010-30P22 Manufacture date 7/90 — 2/91 (17/16" NA & TT Nabco)
46010-45P00 Manufacture date 9/91 — 9/93 (1" NA TT Tokico)
46010-45P00 Manufacture date 2/91 — 9/91 (1" NA & TT Tokico)
46010-45P20 Manufacture date 9/91 — 9/93 (1" NA & TT Nabco)
46010-45P20 Manufacture date 9/93 — Up (1" NA & TT Nabco)

I would go with the 1" BMC. 17/16 might not have the brake pedal feel you like. Response will also be slower if you are modulating the pedal.
found this:


"Checking the Nissan parts books, the Z32 300ZX shares the 240SX's master cylinder design, but comes in 1-inch and even 1 1/16-inch sizes. Wanting a big change in pedal feel, we went for the bigger cylinder (part number 46010 30 p21) This would increase pedal effort by 65 percent. (The 0.99-square inch bore would make 101 psi at 100 pounds of pedal force, or need 165 pounds to make the same 167 psi the stock cylinder made at 100 pounds.) Since the bigger cylinder pumps 65 percent more fluid for the same stroke, it would also significantly reduce pedal slop.
Nissan has always used two suppliers for its brake hydraulics, Nabco and Tokico. The part number we listed is for the Nabco part, but be sure you're clear about what you want or the dealer may substitute the Tokico part. Though the parts are functionally identical, they aren't exactly the same. The 1 1/16 master cylinder only came on cars with ABS, and those cars only needed two brake lines from the master cylinder--one for the front wheels and one for the rears.
Non-ABS cars had three lines, one for each front wheel, and one for both rears (it was split into two at the rear of the car). ABS cars had the extra front brake line port plugged, but here's the difference. On the Nabco cylinders, a simple hex-key plug is used, so an Allen wrench can be used to remove it. After that, the 240SX brake line goes right in. The Tokico cylinder, though, uses a five-sided plug. We were only able to remove the plug after hammering an oversized TORX socket into the five-sided hole.
That's when we discovered the second problem. The hole is machined for a Volkswagen-style bubble-flare brake line, not the standard Nissan reverse-flare. In other words, if you get the Tokico cylinder, be prepared to fabricate some brake lines."
From the Sport Compact Car web site.