Guage cluster with tachometer

What do I need to change or modify to get a guage cluster from a 87 SPX MM to work in my 91 MM. The only reason I want to use it is because I like having a tach and I like guages, not idiot lights, Thanks

i dont think you have to do anything but not totaly sure there might be a plug somwhere that needs to be pluged in on the firewall i think? i just scored a tach cluster and the junkyard and when i took it i took the plugs too and i compared the plugs to my trucks non tach plugs and there was extra wires on the tach cluster plugs. but i put it in and everthing seems to work except i cant start my truck because theres no gas tank in it. there was a write up about it on mightd50 but that website is no more. im gona start my truck this weekend and see if it all works.

i will need similar info....as i'm planning on swapping a tach cluster into my 87 ram 50. my truck has power brakes, but everything else is manual and no a/c.....i plan to keep it this way except for a 2.4 or 3.8 swap, trailing arm rear suspension w/ sway bar, tach cluster, etc.