T170 B or C

[ActionYobbo]

I have the choice of a B ratio or a C ratio T170 to put behind the 239 in my 39 truck. What ratio would be the best B or C?
Thanks

 

[FlatTopFreddie]

B - 27.6 is ideal
I have a D(41.1) in my 36 Coupe 221cu with 3:78 rear end … really nice on the highway . Also have C(37.9) in a 31 Model A also 3:78 rear end.

 

[Mart]

Good info here.

https://www.fordgarage.com/pages/TremecT170FT.htm

Mart.

 

[glennpm]

Good info here.

https://www.fordgarage.com/pages/TremecT170FT.htm

Mart.

Great reference material