Gear ratios for towing

!ton327 · Dec 20, 2014

So today i was making dump runs and my truck **** out the center pin in the spider gears and took out a couple pinion teeth with it so im looking at grabing a complete rear end so what would you do? MY truck is a 78 ford f250 2wd with a 30 over 460,c6, dana 60 ff 3:53s with 245/75/16r tires ,it moves but is kind of a turd towing, what are your guys thoughts? stock or 3:73 or 4:10s thanks for any input. :beer:

Totalled · Dec 20, 2014

I would compromise on 3.73s. I have 4.10s in the green '73. It tows like a beast, but turns 3,200 at 60 on the freeway...

!ton327 · Dec 21, 2014

Totalled said:
I would compromise on 3.73s. I have 4.10s in the green '73. It tows like a beast, but turns 3,200 at 60 on the freeway...

yeah thats what i was thinking pat mine is about 3500 ish at 70 but thats only heading south which i don't do to often

leadfoot067 · Dec 21, 2014

3.73:awesomework:

pokey · Dec 21, 2014

4:10s going from 3:50 to 3:73 won't make much of a difference not worth the cost or effort.

Lucky Jeff · Dec 21, 2014

Another vote for 3.73's. I had 4.10's in my 77. Too much RPM on the freeway.

skinny_pedal · Dec 21, 2014

With those small tires I also say 3.73, maybe 3.90 if thats an option. If you had a 265 or 285 id say bump up to 4.10.

But if you dont drive but couple times a month, gas is cheap now. F*ck it, go 4.10 and poor the beef to it

junkyard jim · Dec 21, 2014

3.73 unless you have overdrive. Go down a tire size when towing for more power.

t1h5ta3 · Dec 21, 2014

of the 2, id go 4:10.... realisticly, if it were mine, and a dedicated tow pig, id be tempted to hit a set of 4:56's....
better gearing = more power and better economy while towing.
and realisticly, the couple hundred rpm diferance should have minimal effect on a 460 if its running well.
besides, would you rather hit a hill and hold 3rd or slow down to grab 2nd?

currently @ 60 mph
3.54 =2600rpm
3.73 =2700rpm
4.10 =3000rpm
4.56 =3300rpm

slow to 45 on a hill...
3.55 =2000rpm
3.73 =2100rpm
4.10 =2300rpm
4.56 =2500rpm

keep in mind the effect of gearing on trans temps as well.... chances are the converter in a c6 below about 2200rpm isnt much more than a heat pump when on a hill... if you bucked up for a low stall tight rv converter you will realy like the lower gearing...

the 2wd 75 f250 i drove years ago had 4:88's in it... tow pig... still managed low teens for mpg with a heavy foot unloaded...

Zoediak · Dec 22, 2014

I would do 4.10's and forget about it...

all of my trucks over the years, even my current chevy has 4.10's and tows great.

The only truck I had that was kind of a pain with the RPMs was my old '64 dodge, but it has 4.88's in it.

Totalled · Dec 22, 2014

Are they really 245/65/16 tires? I have 245/75/16 tires on the '73 and they seem a tad on the short side.

Maybe when I get the '73 back from my step dad you can take it for a cruise to see if that helps you decide.

!ton327 · Dec 22, 2014

Totalled said:
Are they really 245/65/16 tires? I have 245/75/16 tires on the '73 and they seem a tad on the short side.

Maybe when I get the '73 back from my step dad you can take it for a cruise to see if that helps you decide.

I just looked at the tire size and I was wrong there 245/75/16 the same size you have

!ton327 · Dec 22, 2014

They are alittle short but they look way better than the old 235/85 size wise

!ton327 · Dec 23, 2014

The engine runs really well and it sucks down the fuel so its never cheap to drive. I do have a overdrive i could put in it but don't feel like it. I drive the truck once or twice a month if that, it just sits the rest of the time. :beer:

messix · Dec 23, 2014

you have an over drive?????

good god !!!! go with the 4:10 or 4:56 and install the over drive.

!ton327 · Dec 23, 2014

messix said:
you have an over drive?????

good god !!!! go with the 4:10 or 4:56 and install the over drive.

I do but it was given to me but not sure if it works or if its missing parts or electronics its been sitting on my shop floor for about a year now , i did just get done swapping a over drive into my nieghbors 64 f100 2wd shorty with a 351 w .

!ton327 · Jan 4, 2015

I picked up a ff 60 with 3:73's with what looks like a Detroit locker in it from p-n-p in tumwater on Saturday so now it's time to get some work done, thanks for all the reply's :beer:

Totalled · Jan 5, 2015

Nice!

zukkev · Jan 5, 2015

Your gonna wish you went 4:10...3.5 to 3:73 is not enough jump tp warrant a gear swap imo...
Also....make sure its a 30spl d60 and not the course spl...

!ton327 · Jan 5, 2015

I got the axle home and tore it apart the gears look good and its not 30 spline like my old diff was and its course spline but its a complete rear end and its back in the truck just need to finish bolting all my airbags back on and fill the diff and bleed the brakes.