You could give the information in the attached a try, your gage is already bad so what's to lose?

www.29buickphotos.com/Repairs/Temp-Gauge-Repair/7802526...


"If it ain't Steel it ain't Real"
"Earth the insane aslyum for the rest of the Universe"
41 1/2-ton, a work in progress
68 Shortbed stepside 327/325hp/700R4