I'll have to crack open my dash and take a picture of it first. which I'll need to do sooner or later to fix my oil pressure gauge.

It's easy to do. Just solder a 10K ohm resister onto the back of the tach circuit board just like the 3.4L tach has.

I've been conned into giving up all my pictures, diagrams and info for a technical article on here (4x4wire) so give it some time and it will all be posted in that article.