speed sensors?
 

at rear of cam cover there is a small bracket with 2 connectors. One end of both go to top of bellhousing; about 8" cables. Connect at bellhousing below heater valve

I assume these are speed sensors; they look pretty beat up from heat.

Question is: anyone know part numbers and can recommend a vendor

thanks

Speed and reference sensors are what you are refering to. They are actually the same sensor, just providing different functions. Auto Atlanta has replacement sensors (R944 606 115 00) at $120, Genuine Porsche (g944 606 115 00) at $180, and used (u944 606 115 00) at $50. (www.***********.com - look on their electrical diagrams, page 13)

(Sorry Pelican - I couldn't find the sensors on your site - maybe someone else can provide Pelicans prices and part numbers)

If the sensors are working just buy one for a spare.