I swapped the 2.73 to a 3.73 in my 91 Z28 with an automatic 700R4. I ordered the correct drive and driven gears to make the speedo correct.

My question is, do I need to change the VSS or can I use the old one?
The factory driven gear was a red, 37 tooth and I am swapping it for a purple, 43 tooth with a gray, 15 tooth drive gear.

Also, could someone tell me the difference in the two VSS sensors that are made for this car?

Thanks so much!!!!

 

I did not have to change the vss when I did this exact swap years ago.

 

Thanks..
I went to the stealership today and they only have one VSS listed for the 91 with an automatic. Service manager told me that it should work regardless of the driven gear that is attached to it.

Do you remember which drive/driven gears you went with?
I believe the 15 tooth drive and 43 tooth driven with a 26 in tall tire will be really close.

 

I'm swaping from a 2.73 to a 3.23 gear. What I need to know is when figuering tire dim.should I measure with the weight of car on the tire or off. I will do the math for figuring the drivegear and driven gear just want it to be right. I RUNNING 225/60/16

 

Just use the diameter of the tire based on the specs... 225/60/16 is 225mm wide which is 225/25.4 = 8.858 inches wide. 60% sidewall to width aspect ratio so 0.6 x 8.858 is 5.315 inches per sidewall. 5.315x2 = 10.623 inches of total tire heights. On a 16" rim so 16 + 10.623 is 26.623 inches tall assembly