I read a thread that compared the part numbers for the 1.6 cam gears and the 1.8 cam gears. The numbers were similar, but not the same. Is there a definitive answer as to whether or not I can swap my 1.6 cam gears to my 1.8 engine with 99 head?

 

The cam gear is the same for all 1.6 & 1.8 NA engines: B6S7-12-425A, according to the '91 and '97 Mazda catalogs.

The NB gear is different because it has the timing bumps in it for the cam sensor to read. Based upon the fact that aftermarket cam gears are known to be compatible across all NA/NB years (excluding the intake side of VVT engines) I see no reason why stock cam gears would not interchange across the NA/NB barrier, presuming you don't need the sensor.

 

Thank you