DDK - Die Deutschen Klassiker

Ok so my 67 I’ve decided to get up in the air to sort out sticky rear brakes. I’m going to replace brake flexis and hard lines jus because calipers possibly depends on their condition. My first question is Any benifit to trying to fit cross drilled disc instead of the std non vented ones.
Secondly I have 2.7 motor with 915 gearbox fitted my only issue is I have no speedo. Stupidly I didn’t look at bottom of speedo till an he of looking for a non existent speedo cable turns out I have electronic speedo and sensor on gearbox. How can I test if my sensor on gearbox is working or if I have further problems
Thanx for your time all

Just my opinion.

For a simple road car cross drilled discs are not going to add anything. I have cross drilled discs on all corners as I used to hillclimb hard my 911 with advanced brake pads.

My car also has a 915 alloy case box, electric speedo (car is a 73T with 3.2 engine). I would think there must be a way to connect the 2 wires leading the to speedo to a meter to see the signal/pulse increasing with road speed, but Jonny hart on here will be far more able to define the test.

I used the 3.2 speedo out of the 3.2 donar car so all works well.

Grab your voltmeter, switch it to AC, stick it across the terminals, get a friend to rotate a wheel. Or if you're feeling particularly brave (or stupid, depending on your point of view) stick it up on axle stands and start it up and stick it in third. If the sensor's working you'll see an output. If it's not, you won't.

Perfect I’ll give a go the weekend with the sensor
It’s never had a working speedo since I got eh car a few years ago always drive it by the rev counter )
As for brakes was jus thinking cross drilled would b a sort of upgrade cos I don’t tend to baby it and like to drive it properly and do a few track events in future

Brakes..
Cross drilled all round, fronts work the hardest and good pads essential.
Had mine on the car for over 10 years, about 18k miles.
Bit dusty, bit noisey too, but it stops!