I got lucky (I guess) and my 1950 F3 has a Dana 60 in it already. I am looking for a bit more speed and a bit less RPM and would like to go more than 45-50 MPH. If you had your choice, which ratio would you put in a Dana 60? It appears to have a 4.88, in it (or so).

TIA

 

With a flathead I'd go 4.11 in a hilly area or 3.73 in a relatively flat area. With a higher power motor I'd go 3.54. Be aware that the Dana 60 has a carrier break between 4.11 and 4.56 so you will need to find another differential carrier to install higher speed gears.

What engine and transmission are you going to be running?

 

Well shoot. I was pondering going from my 4.88 to 3.73, but it looks like I can't just change the ring and pinion.
That's a bummer.
It might just be easier and cheaper to buy one. Just did a quick search and found one. For $200 I doubt I could get the ring and pinion let alone get it installed. Dang.
https://stlouis.craigslist.org/pts/d...212463284.html

 

I guess that I can muck up the decision by adding that I have a EAC Merc Flathead already rebuilt and ready to go in someday. Should be 150ish horse with what we did to it... not killer power, but would that lean more towards the 3.54?

I will probably still use the crashbox. I would pay good money (more than market) for a Ford T98, but they don't seem to exist anymore. In any case 1:1 final.

I would just be happy with 10 more MPH... you can get killed around here if you are not going 55 on the two lane highways - they are flat and open.

Thank you for you responses.

 

Do I need to go pick it up for ya Joe?

 

I think I'd go with something around 3.73. Around 3.50 is good in an F-1, but you have more weight, likely taller tires, and painful downshifts.

 

We put in a Dana 60 with 3.55 gears , with the T5 transmission behind the Flathead highway speeds are no problem but I don't think she would do so well in the mountains . 373 might be a good choice if you can find one .

 

It depends what transmission you have. I have a 4.10:1 with a 4R70W overdrive (30%) transmission and it runs great.

 

I'm running 3.73's with tires just shy of 32" tall, a T98 and a really tired Flatty. About as tall a gear as I can use because I use my truck like a truck. I can do a little over 65 mph. If I'm really loaded and starting out on an incline I need to use 1st gear to get rolling. Empty starting out in 2nd is fine. I think 355's would be hard on my clutch.

T98's are out there. I went from Tucson to Oklahoma to get mine. Looked at a few Express Bed's too. F2's and 3's take more searching for some of the stuff we need compared to F1's.

 

Also be aware that the Dana 60s got wider in 1973. For the correct width you want a 1972 and earlier axle. The one you found could probably be used as a parts donor to re-gear an earlier Dana 60.

 

Yeah, I noticed that after I posted it. I'm in no rush for different gearing.

 

Spicer/Dana 60 Ring & Pinion:

1956/62: 4.56 & 4.88; 1963: 4.10 = 10 splines.

1966: 3.54 & 4.10; 1967: 3.73 & 4.56 = 29 splines.

 

Thanks everybody. I have a plan now. 3.73 it is. I have a 4.56 in there now... took the the cover off yesterday.

 

How exactly is it wider? Is it the whole axle is wider so the wheels will stick out further? I am trying to find a new rear end for my 49 Mercury M68 but everything is in the mid 70's range.

 

That's exactly the problem. And not by just an inch or so either. It's enough that fender interference issues are a very real possibility with a stock type wheel.