FJ40 Smog Pump Differences (1 Viewer)

[jrcfj40]

Does anyone know the difference between a 1977 smog pump and a 1979 pump?
Looking at the pictures it appears the casings are the same with the exception of the piece circled in red. I was wondering if a 1979 smog pump can be used in place of a 1977 without hindering or altering functionality.

Thanks!
Jeff

 

[FJ40Jim]

75-78 pumps have a cast-iron pulley that slips on a keyed shaft and is retained by a REVERSE threaded nut.

79-80 pumps have a stamped pulley that is bolted to a flange with 3 small bolts.

Stuff may be different on California smogged engine's.

 

[65swb45]

Dimensionally they are the same.