Thick or thin gears?

[pomai]

I have a 14 blt ff, 4.10 gears with an oper carrier from a 1980 chevy 1 ton truck that I will be installing into my 88 Blazer. I want to install 4.56 gears. How can I tell if I need thick or thin gears. Thanks Ed

 

[pauly383]

Well according to this , you need a new carrier for 4.56 , so I say you need thick gears to use your carrier .

14-7/8 x 13"
14 HOLES
Irregular Gasket Pattern
​

SPECIFICATIONS

• RG Diameter 10.5"
• 12 9/16 X 18" RH Threaded Bolts
• PINION Diameter 1.75", 30 Spline CASE: 4.10 & Numerically Lower, 4.56 & Numerically Higher
  
  8620 Material Heat-Treated
  
  Assembly Specifications:
  
• Cover Bolt Ft. Lbs. 20
• Pinion Brg. Preload In. Lbs 20-25
• Pinion Brg. Preload In. Lbs 10-15 Used
• Ring Gear Backlash .005-.009
• Ring Gear Bolt to case Ft. Lbs. 105
• Side Brg. Caps Ft. Lbs. 100

 

[sled_dog]

thick gears. DOn't bother looking for a new carrier. Thick gears are easier to find than thin so the best 14 bolt combo is 4.10 down carrier with thick gears.

 

[BurbLover]

Not to mention thick gears are usually cheaper than the thin ones.