THE ESSENTIALS
MAKE: TUDOR
MODEL: 9430/0
YEAR: 1978
BOX/PAPERS: YES/YES
CASE DIAMETER: 40mm
CASE MATERIAL: STAINLESS STEEL
BRACELET MATERIAL: STAINLESS STEEL
MOVEMENT: AUTOMATIC
In 1976, Tudor launched its third series of chronographs. Enter the “Big Block” chronographs—the beefy successors to the slimmer, funkier Monte Carlo chronos of the 1970s. While the Monte Carlo (and Rolex’s Daytona of the same era) were still stuck with manual-wind movements, the Big Block arrived with an automatic caliber, putting Tudor ahead of the curve. Fun fact: Rolex didn’t fit the Daytona with an automatic movement until 1988—a full decade later.
Tudor also added something its big brother refused to offer: a date complication. The “Big Block” nickname itself comes from the extra-thick mid-case, upsized to accommodate the Valjoux 7750 automatic chronograph movement.
Now, let’s talk dials. Normally, underneath the “Tudor” logo you’d find “OYSTERDATE.” But on this version? Nothing. Just a wide expanse of empty dial real estate—hence the name “Solo Dial.” It might look like a printing error, but it’s actually the earliest execution of the 9430/0 Big Block—and it’s exceptionally uncommon. In fact, this is only the second example we’ve ever encountered in the flesh.
This particular watch is in superb condition. The case is outstanding—so sharp it could pass for unpolished, though it has seen a light refinishing at some point. Our guess, based on the finish, is that it was done in-period, as the chamfers remain correct and the crown guards are virtually untouched aside from the top surface. The dial shows mild staining around the rehaut, but the rest is spotless with all markers intact. The hands remain clean, with their tritium plots preserved. The watch is fitted with the correct service 7836/380 bracelet.
Originally sold in Newcastle, the watch comes complete with its inner and outer boxes, wallet, papers, translation documents, original bill of sale, Rolex service paperwork, and booklet.
Fresh from a service just weeks ago, it is running at -4 s/d, 285 amps, with a beat error of 0.2 ms.