81 zx 2+2 tranny for 73 4 sp?

[wa5ngp]

I read thru the forum and I have about concluded that I can trade out an 81zx 2+2 5 speed for my 4 speed 73 240z. Keep the same drive shaft but use the diffy from the zx as well. Does all that still sound good? I saw some scares about shifter holes but apparently that only applies to the early 240s.

I've talked about doing this for years but now that my clutch is slipping in the 240 the tranny has got to come out anyway and I'm retired now so I should have the time. Not really looking forward to being covered by grease but I guess that's the price.

Only gotcha may be the speedo gear. Anything else?

73 240 bought in 76 (daily driver)

81 zx rustbucket no longer a daily driver

regards

Don

[Walter Moore]

On a 73 you are correct. The 81 transmission and differential will fit. There may be some issues with mounting the differential related to the mustache bar, but if you do a search on the subject I am certain the information you need is on this site, or perhaps HybridZ.

The holder for the speedometer gear is different between your transmissions, and the ZX gear may not be accurate with your early speedometer. (I don't know what gear the 81 has, but the 83 I bought had an 18 tooth gear) Per the FSM, on a 71 the 3.90 differential requires a 19 tooth gear. I don't know without some research if that is true on a 73.