Tap into wires at the gauge cluster for speedometer and tach?

I'm finishing up the wiring for my swap and need to hookup the tach and speedomete wires from my swap harness. My harness comes into the cab right next to the steering column. Can I tap into the wires behind the gauge cluster for them? Does anyone have a pinout for a 95 k1500 work truck?

I would do it on the outside, like that is becomes part of the harness. At least that is the way my '90 is.

i tapped tach at coil connecter under hood and speedo behind cluster. i used alldata for he wire diagram