Speedometer Gear Interchangeability

Hi I'm the owner of a 06/1972 240z with stock 4 speed b-style transmission and 3.36 differential.  I recently went to change the gaskets on my speedometer gear, but unfortunately when reinserting it forced it in, causing the teeth to strip out.  I am now in the process of looking for the (stock) 16 tooth yellow speedometer gear but am unable to find one online.  With that thought in mind, my speedometer does read high (8 mph or so over at 70 mph) due to my slightly larger tire setup (195/70r14).  I am now considering the black 17 tooth speedometer gear, but unfortunately cannot find just the drive gear online.  My only options are a 17 tooth with the different style housing (what looks to be aluminum), which I have read has a different overall length.  Would it be possible to swap the speedometer pinion gear from the later style speedometer gear assembly into my stock housing? Or will this later style fit?  Looking for ideas/possible people with an abundance of 16 or 17 tooth speedometer gears!