I went a different route with mine. Seems to me that those boards are old enough that they may have deteriorated, and the connectors put physical strain on the board. So instead, I soldered lengths of wire to the board pads, which do NOT "hang" on the board like original, and brought them out to Molex -style connectors I bought at Radio Sh##
Generally, here's the issues I ran into
Make SURE you jumper gauge power (output of the voltage limiter) across between boards.
It is a good idea to ID the ground paths of the boards and bond them together with small wire, jumper between the boards, and then bring the ground out on a long pigtail which you can then ground to the dash brace behind the cluster
Be sure to tighten/ loosen/ tighten all mounting screws, and while you have it apart, clean the copper and cluster where they mount
Be sure to clean gauge stud mounts int he board, and tight/ loose/ tight the nuts to scrub them clean. Good idea to use star washers and "real" nuts
Examine carefully the brass fingers for the voltage limiter. Mine were not making contact with the board. Either solder the brass "jumper" across to the copper board traces, or use short lengths of wire to solder between and make sure of contact.
Clean the board where the lamp fingers touch the board, and test all lights before you install the cluster
When installing the voltage limiter, work it in/ out several times, to scrub the connections clean. Not a bad idea to use "no-ox" or other electrical dielectric grease on the connections.
Take your time and do it once