What is the difference between the Lightning rear axle, and the plain jane one under my 93 (stupid 3.08 gears)?? I am wanting to upgrade to 3.73 or 4.10 gears to help me with towing.

 

The 8.8 in the Lightning has larger 31 spline axles and built in cooling fins.

 

All F150 8.8" diffs are 31 spline. Are there other differences?
I'm guessing there might be spring perch issues, given that the Lightning has a slightly different frame

 

Are they geared lower?

I really want some lower gears for my truck, and don't really want to buy new gears.

 

A 4x4 with manual trans should be a 354 gear set. Not to hard to find in these parts.

 

93-95 Lightnings came with 4.10's

 

So would it be an easy swap?

I mean the lightnings weren't that much different, were they?

 

What are you planning on doing about the front diff? You need to change it too or you'll never be able to use 4WD again.

You need to measure the size of the spring perches on your truck and the perch to perch dimension and compare that to any Lightning you find. The Lightnings were built on with frames and suspensions that mixed 1/2 ton and 3/4 ton parts to get greater torsional stiffness. That may have made the spring perches different in size and/or location. You'll have to measure to know.

 

I must have misled you, my truck is only 2wd.
yep just a run of the mill 2wd F150, but I am baffled why Ford would put a 351 in a truck with 3.08 gears, I mean if I was buying a truck with that gear in the rear I would have got a 300 6 cyl.

I want to be able th make this truck pull a car trailer (500 miles or more) with my Jeep (Comanche on 35s) on it and the bed full of camping stuff, firewood, and spare parts (for the Jeep). I also drive it to work every day (for now). I put on the hellwig overload leaf spring kit, and am planning on removing that and going with air bags. I may just go with 3.55 gears (an axle swap is easier than a gear swap), and if I don't like that then I will go to 3.73 or 4.10.

I should just sell the truck and get a newer F250.:santa:

 

If you use a Ford Racing gearset the gear swap is really easy, just measure for the correct size pinion shim and throw it together, all the other dimensions should come out right. It would be easier than trying to find a lightning axle.

-Jon

 

FWIW RPM @ 65 MPH with stock tires:

2.73 1516
3.08 1710
3.27 1816
3.55 1972
3.73 2071
4.11 2283

 

i have an 87 5.0 w/ 3:55 l/s, i beat the s**t out of the rear and its still going w/ almost 250,000, i've owned the truck for like 20,000 and am replacing the gears soon....i go on the highway alot and i need that red light torque so what do i do its 2wd, 3in lift, 4sp manual, e-fan, pullies, tb,spacer, no smog, and soon to be true duals i have the kit ready on standby so 3:73 the way to go.....im thinkin 4:10 is too much for on the highway..my buddy had them in a stang and at like 70mph in 5th gear he was at like 4800....so a lil help here please???????


:edit- i will only be running 30-31 inch tires on it

 

are you sure about that? because when i was ordering axles they asked me if it was 31 or 28 spline then i told them it was a 31 spline lightning axle and they got me what i needed

 

28 Spline in Mustangs and Rangers, 31 Spline in F150s
Can't tell you for sure about other models

 

AFAIK, there's no difference in pre Lightning rear suspensions/axles & any other '80-96 1/2-ton.



I suspect it's just that super-low ratio.

BTW
I have no trouble pulling the world with my 3.08s & 32s; they're physically MUCH stronger than 4.10s, and with the ultra-deep granny gear in my NP435, torque isn't a problem. The high gears make up for the lack of OD.