Found this on-line. Thought it may be nice to have posted for everyone's benefit. I assume the factory B3 is also 50mm...................
90-94 Mazda 323 SOHC 8v 1.6liter (B6): 50mm
90-94 Mazda Protege SOHC 16v 1.8liter (B8-ME): 55mm
90-94 Mazda Protege DOHC 16v 1.8liter (BP): 60mm
92-93 Mazda MX-3 SOHC 16v 1.6liter (B6-ME): 55mm
94-95 Mazda MX-3 DOHC 16v 1.6liter (B6D): 55mm
91-96 Ford Escort GT DOHC 16v 1.8liter (BP): 60mm
91-96 Mercury Tracer LTS DOHC 16v 1.8liter (BP): 60mm
91-96 Ford Escort LX-E DOHC 16v 1.8liter (BP): 60mm
90-94 Mazda 323 SOHC 8v 1.6liter (B6): 50mm
90-94 Mazda Protege SOHC 16v 1.8liter (B8-ME): 55mm
90-94 Mazda Protege DOHC 16v 1.8liter (BP): 60mm
92-93 Mazda MX-3 SOHC 16v 1.6liter (B6-ME): 55mm
94-95 Mazda MX-3 DOHC 16v 1.6liter (B6D): 55mm
91-96 Ford Escort GT DOHC 16v 1.8liter (BP): 60mm
91-96 Mercury Tracer LTS DOHC 16v 1.8liter (BP): 60mm
91-96 Ford Escort LX-E DOHC 16v 1.8liter (BP): 60mm