3.07 vs. 3.54

[draginmopars]

anyone run a 3.07 with a 5 speed

have a 92 with a 3.54 gear > getrag
thinking of swapping in a 3.07
I have a complete rear end under another truck( has a 727)

Would that be a good or bad idea
due to the gear ratio of the 5 speed

I usually use 2nd to take off

With the 3.07 would I have to use 1 st


Thanks

[Bodacious]

IMHO, the 3.54 ratio is the perfect ratio for the 'ol 12 valves. I ran an NV4500 and 3.07 gears for years and really liked them...at least while I was running a very short tire.

You can run a 35" tire with the 3.54 and obtain dang near the same ratio as the 3.07 with stock 30" tires.

The 3.07's will yield unreal mileage while cruising anywhere flat in overdrive.

I would not swap the rears.

[56cummins]

What is your tire height?

[Mark Nixon]

There comes a point of diminishing return, where turning too low of RPMs makes the engine work more, sacrificing fuel mileage.
More gears in the transmission combats that somewhat, but at the end of the day, I believe the magical number is 2,000 RPMs.

Anything slower makes the engine work harder, while much above 2400 spins it harder than it needs to.

3.07s and towing heavy, with a 5 speed, is not an ideal combination with a stock tire size, mainly because of the gear split, which a taller tire makes worse.

One other thing about 3.07s in a Dana 71 (70u).
I have yet to see a high mileage 3.07 axle that didn't seem to have a ton of backlash, which indicates gear wear, and that 3.07 gears in a Dana 70u don't like heavy loads.

Mark.

[Loaded burrito]

Mark hit it on the head. I have had 2 trucks with 5sp 3.07 and one with rh and 3.07 and hated them

[56cummins]

If this is on his Satellite with a 31'' tire or less it might work best to have 3.07.

[draginmopars]

Originally Posted by 56cummins

If this is on his Satellite with a 31'' tire or less it might work best to have 3.07.

No, I have a 73 car hauler converted to CTD / 5 speed
with a 3.07 , still under construction



My 92 CTD 5 -speed, 11" steel flat bed
has a 3.54
that is the one I'm thinking of putting the 3.07 in
putting the 3.54 in the car hauler

The Satellite,> 90 Cummins / 727 with a 31" tire
I have not thought about what gear to change to
have a 3.73 and a 3.54
stock for now, in process, of mods, right now, in the engine> gov spring 3800, 60 lbs springs
head porting, later a bigger turbo



https://www.youtube.com/watch?v=RxrriOfjYAY

Thanks for all reply's, it's helpful for me

[draginmopars]

Originally Posted by 56cummins

What is your tire height?

I have not measured it
235 / 75-15

[Mark Nixon]

As a man who used to own a wedgebed Club Cab carhauler, who hauled trucks and trailers with it, 4.10s would be your best friend!

Mine had 4.56s with a Non-Intercooled Cummins 5 speed.
4.56s were a bit much (tallest gear I had at the time-swapped out 4.88s!), but it would still run 80 mph after tweaking the pump up a bit and get 16 unloaded doing it.
It never dipped below 11 mpg fully loaded, dragging a trailer.

Mark.

[Bodacious]

Originally Posted by draginmopars

No, I have a 73 car hauler converted to CTD / 5 speed
with a 3.07 , still under construction



My 92 CTD 5 -speed, 11" steel flat bed
has a 3.54
that is the one I'm thinking of putting the 3.07 in
putting the 3.54 in the car hauler

The Satellite,> 90 Cummins / 727 with a 31" tire
I have not thought about what gear to change to
have a 3.73 and a 3.54
stock for now, in process, of mods, right now, in the engine> gov spring 3800, 60 lbs springs
head porting, later a bigger turbo



https://www.youtube.com/watch?v=RxrriOfjYAY

Thanks for all reply's, it's helpful for me

Cool as $hit right there!!! Stick with the 3.54's.

[draginmopars]

I was asked
"what's on the back of the Hauler"

It's a 84 Dodge (of Course) Rampage
With a Shelby Charger front clip

Was my "parts Runner"
one day I noticed a gas leak
the fuel tank had a pin hole, and the unibody was splitting at the seam



so, the only way to fix if
was a Real Frame



to make it Haul> added 4 extra cylinders.. lol



some fatties for traction



need to finish the electrical, fuel system and interior sheet metal work.

[Mark Nixon]

Yep, the BEST junk is recycled junk.
If you go with 3.54s, you'll be happier with a 6 speed.

Mark.

[Mooner1]

Draginmopars..I like yer style sir. That Rampage is awesome! I'd think the 3.07's in your satellite and 3.54's or 3.73's in your car hauler would be just about perfect in my humble opinion. Which that car hauler is just plain old school bad-assery by the way.

[draginmopars]

Originally Posted by Mooner1

Draginmopars..I like yer style sir. That Rampage is awesome! I'd think the 3.07's in your satellite and 3.54's or 3.73's in your car hauler would be just about perfect in my humble opinion. Which that car hauler is just plain old school bad-assery by the way.

Thanks,
Looks like a plan

Yea, the Satellite has a 4.56> left over from it's gasser days
I knew it was the wrong gear, BUT, had to try it. just to know what it would do >>>60 mph.....lol



Any body >>>Do they make a spool to fit the 3.07
would a 4.10/ down fit ?
I need to know before cutting the Dana 61 to fit the Satellite

Would I have to use a spacer?
like using a spacer for a 4.10 gear on a 4.56 /up spool

I'm not a fan of using the spacer

If it won't, then I'll find another use for it
It's a Cab/chassis dual wheel rear ( out of a box truck)

Then
I'll have to use the Dana 60 with a 3.54
Would still have to buy a 4.10/ down spool ?

Anyone have a spool for sale ?

Thanks again
for all the info
Yea, I'm green behind the ears....

[chevota84]

Imo, your best bet is to build a 9" for it. The 61's get pretty goofy on finding parts.

Sent from my SM-G930V using Tapatalk

[Mark Nixon]

I believe I read somewhere that you can use the 4.56 and deeper carrier (spool) on a 3.07 axle, but don't quote me on that.

Mark.

[Mark Nixon]

Originally Posted by chevota84

Imo, your best bet is to build a 9" for it. The 61's get pretty goofy on finding parts.

Sent from my SM-G930V using Tapatalk

I 2nd that!
You can even drop way down into the 2.70s, possibly lower, on gearing.

Mark.

[JQmile]

3.07's will be the ticket in your Satellite, I have some in my '89 and I really like the setup. It has a Detroit locker in the rear, that needed shims to fit because I ordered the wrong one, but either one would have worked. Those 3.07 gears should at least get you through the 1/8th mile.

[draginmopars]

Satellite info-----

I got some time to remove the trans brake > let it shift on it's own
then changed the rear to a 3.55 > had a 8 3/4 already set up

still need to remove the collar from the power screw......More Fuel

First 2 passes> don't know what I was thinking
am so use to getting the engine temp to 160 > for the Dart > E-85.
1-2 pass @ 5 psi boost

3-5 pass got engine temp up to 180
3-5 pass @ 7 lbs boost > all the brakes could hold

Still running "up against the stock governor" 3/4 track)

[malibu795]

Nice!!