39 ****** 40 rearend

[30ratrodder]

Hi All
What weight of gear oil do I need to use in a 39 top loader ****** and a 40 banjo reared? Thanks

 

[MuskegonFlatheadFan]

i use 90-145

 

[Vic Piano]

I use 85-140 in the transmission and rear on all our Flatheads except the '53 Ford-O-Matic...