Jag 3.54 and 2000 speedo head

[corazon]

Just thinking around the speedo issue with the ZF box swap.
As a quick solution can I not just drive a 2000 speedo from the 3.54 jag diff output running a long cable front to back?
Thanks
Jim

 

[harveyp6]

You'll need to sort something as regards the speedo calibration once the ZF goes in. If you are changing to a Jag 3.54 then just wait until that's in before you send the speedo off. If you already have a Rover 3.54 diff, then changing to the Jag diff of the same ratio won't make any difference to the speedo reading.

 

[corazon]

Harvey, I have the standard V8 diff (3.08:1?) with V8 speedo.
If i just swap my V8 speedo for a 2000/2200 one when the jag diff goes in and take the output from there, it should be accurate in theory..?
It would most likely be a temporary solution, but a quick and easy one if so..
Jim

 

[harveyp6]

Harvey, I have the standard V8 diff (3.08:1?) with V8 speedo.
If i just swap my V8 speedo for a 2000/2200 one when the jag diff goes in and take the output from there, it should be accurate in theory..?

If you're looking for a temporary solution when the car still has the BW35, but the Jag 3.54 diff is fitted, then just changing the speedo head should bring the speedo accuracy back to what it was before. AFAIK all the P6 auto speedo drive and driven gears are the same. No need to do anything with the cable at that point.