guage cluster swap ?

[big black diesel]

I have a 1994 K2500 with 6.5 and no tach on my gauge cluster. Does anyone know if these trucks are pre wired all the same ? Could I swap my cluster for one with a tach and have it work ? or will I just have to add an external tachometer ? :confused:

[racer55]

I would expect the wiring is there to swap clusters-the tach runs off the alternator and the engine harness should all be the same so no reason to think the rest is different.