Instealling late mod MM "Sport" gauges in 87 D50?

[FMS88]

The harness connections to the carburetor and FI models are different. The 87-89 clusters have three connectors, the 90-91 have only two. If the 91 configuration applies to subsequent years, some rewiring of the '87 will be needed. You definitely want a cluster out of a 4x4 if you want those lights to work. Here's the cluster schematic for '88 and '91 model years:

Correction: The statement and schematic that the FI versions have only two connectors are incorrect. There are three three connectors to 90+ years, each with the same number of potential wires appearing in the '88 schematic. The '91 schematic is wrong. For the correct schematic see my post of 02-01-2019 below.