Tach from C60 to R10 ?

[BLE 'BURBAN]

AMP gauge or VOLT gauge? MECHANICAL or ELETRICAL OIL gauge?
If it is AMP/MECHANICAL then not without a lot of work. As for the tach, you'd have to swap out the motor for the tach it's self (behind the faceplate) for one that's out of say an S-10 with the 4.3L or send the tach off to have it reworked to work with the 6 cylinder Unless of course the donor C60 had a 6 cylinder then I THINK IT MIGHT WORK BUT DON'T QUOTE ME ON THAT. jUST SPECULATION ON MY PART.
I did a similar swap 3 years ago but in my 90 burb with an electronic speedometer. Had a couple issues with the tach at the time but since I had a good working V8 factory tach I swapped out the face plates, played hell getting the needle reset right, but it's all still working just right.

Oh and you WILL have to repin your harness that plugs into the back of the cluster.