how to change the gear that turns the speedo cable ?

[beforeandafter]

also what donor trans can i use the gear from i have a 86 grand national

 

[SSedan64]

also what donor trans can i use the gear from i have a 86 grand national

If you live in an area with corrosion, road salt etc.. You should start by spraying/soaking the speedo bullet/housing with some kind of penetrant. Work the bullet back & forth to try and loosen it while prying it out. The 2 dissimilar metals aluminum/steel can corrode together.
Stock Driven gear is 29-tooth. Vendors on the TB site may have them.

TCI - TECHNICAL INFORMATION: Speedometer Gears
Speedometer Gear Chart 200-4R
Speedometer Gear, Speedometer Gears, Ford, GM, Dodge 700R4

 

[pacecarta]

heres the gm part #s and gear tooth count for the Gn if replacing for stock

keep in mind this is for stock Gn BRF 2004r with 3.42 rear gear and stock height 26" tires


drive gear
11 tooth
original GM part # 83634965

driven gear
30 tooth Blue
original GM part # 25524925