Big Block

The Tudor Big Block holds a special place as Tudor’s first automatic chronograph, debuting in the 1970s as an affordable alternative to the Rolex Daytona but with its own identity. Collectors value its heritage, especially as it introduced the robust Valjoux 7750 movement to Tudor’s lineup, offering a combination of performance and vintage charm. The Big Block’s distinctive thick case profile—hence the nickname—sets it apart visually and on the wrist, making it a conversation piece among sports chronographs.

Key references include the 9420, 9430, and 79180/79170/79160 series, each with subtle dial and bezel differences. The earlier 9400-series models feature plexiglass crystals and “Monte Carlo” dials, while the 79100-series (introduced in the late 1980s) bring sapphire crystals and updated dial layouts. Variants with exotic dials, such as the "panda" or "reverse panda," tend to command higher prices, as do those in original, unpolished condition with matching bracelets and box/papers.

Expect a 40mm steel case with 200m water resistance—unusual for a vintage chronograph—making the Big Block practical for daily wear. The Valjoux 7750 automatic movement is reliable and serviceable, but check for correct period parts, as hands and bezels are sometimes swapped during servicing. When shopping, prioritize originality and clear provenance, as these are the main drivers of value with this model. The Big Block remains a compelling choice for anyone seeking vintage chronograph pedigree without the Daytona premium.