I have a stock 1950 F2 with flathead V8 3 speed on floor. Does not like to run much over 55mph..rpms are maxed out. Have tires within 1 inch of stock hieght. The shop book says it can have either 4.11 or 4.857 gears in it.
How can I tell without tearing the rear end apart? I want to keep it stock and not change rear ends. Chuck's trucks has a 4.11 set, just need to know what I have now.

 

The stock ratio was the 4.86/1. I've heard of a handful of 4.11s having been found but it's literally a handful. Four or five. It's common for the ratio to be stamped into the differential housing. If you don't find it you can determine it by blocking a rear wheel, jacking up the other side, chalk mark the elevated wheel and drive shaft, then rotate the wheel TWO turns counting the drive shaft's revolutions. Almost five is the 4.86/1, slightly more than four and you are a winner. IMHO you're already a winner having the 3HD tranny since it is synchro on 2nd and 3rd.

I have Chuck's 4.11s in both my front and rear axles. Stu

 

Thanks Stu. I will check the wheel rotation out. I will also look for stamped numbers on axel.
How hard was it to change gears?

 

Ummm, easy for me. Chuck did it. He's described it in other threads, though, for other guys that have done theirs. You might do a Google search. Stu

 

Here is a thread with pictures and description of a truck owner who purchased and installed one of Chuck's 4.11 kits: https://www.ford-trucks.com/forums/1...onversion.html

Here is a second thread with a 4.11 kit install: https://www.ford-trucks.com/forums/1...mission-4.html