Working on a 1985 Mustang GT 5 Speed car. I was investigating the Up Shift light in the dash because it is not working. After some research I realized it was designed to improve fuel economy and turns on when several parameters are met and at about 2000 rpm.

Since that is less than helpful, I was curious if anyone has replaced the upshift module with an RPM Activated Switch like the one from Summit (SUM-830453)? The goal would be to have the in dash shift light operate at a programmable RPM (like 6000). Any issues that I need to be aware of? Thanks.