UPRADE HELP WITH AFTERMARKET TEMP. gauge (1 Viewer)

[1COWBOYROY]

IM NEW TO THIS SITE

i have a 98 tacoma 3.4L , I BOUGHT a dual gauge set up for a pillar pod
i wanted to go around idiot temp gauge, and had no oil gauge
HOW DO I PLUMB the temp probe or adapt from what apeaers to be 8mm sending unit to ????? what size for old style mech. temp gauge

I APPRECIATE ALL HELP

 

[1COWBOYROY]

Does anyone know the exact size of factory sending unit, for 98 tacoma 4x4 3.4l
thanks again