Hello KDAR 353. It's funny that you posted a need for the tach driven gear for your Darrin at this time.
I believe the gear you are looking for, referring to your pictures, is the spiral driven gear. It so happens that I was just able to get one of these gears made. I removed my old gear from the case and put in the new one, mounted it on the distributor and connected it to the dash instrument. Then ran the engine for 30 minutes and it worked great with no noise.
This particular gear can be made on a one order basis. But due to the run time for cutting the spiral gears the gear would cost $150.00 each. (If any one is interested in a cost breakdown let me know as I have it).
From the picture you posted it appears that is all you would need. I've done a lot of research on this and believe that we can make our tachs work by replacing just the spiral driven gear, ok?
You can contact me by email @
kvagabond@geusnet.com or by phone 903-268-3129.
