Ford Muscle Cars Tech Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Ive got a 65 mustang which Im putting a ford 9" axle. Im going to rebuild it my self but I dont know what spline I should use 28 or 31? I will be using the car for cruising and maybe the drags.
 

·
Registered
Joined
·
659 Posts
go 31 and not worry.
 

·
Registered
Joined
·
2,187 Posts
What size of motor and what weight of flywheel?

The standard 28 spline axles are pretty tough. Will easily take a hard launch from dead stop with small to medium H.P. engine. Unless you are expecting to develop 600 H.P. the standards ought to work.

Wm.
 

·
Banned
Joined
·
2,833 Posts
If you're worried get some 28 spline forged axles made up. 8" is lighter and already is installed. 31 spline change over will cost some $$$$. Unless you're making mega HP and slicks you won't have a problem.
 

·
Registered
Joined
·
493 Posts
If you're building from scratch with no axles or differential already in your parts-pile, I would definitely go with 31 spline and as already said -never really have to wonder about it again.

If you've got a salvage unit with 28 spline axles already in it, then you need to look more carefully at budget and the power & way the car is used... Look at the 'Project '67 / Project 11.99' car in FordMuscle's project cars to see what 8" and then 9" with 28 splines will or may hold up to.
 

·
Registered
Joined
·
182 Posts
No reason to pick the 31-splines unless you gonna put serious horsepower and slicks.
There is no way to twist of a 28 splines axle with regular tires and ln the medium HP range.

I have used all of Ford 8'' thrugh 9'' axles with different splines and there has never been any problems.
Even the weaker 8'' with 28 splines hold up for 400Hp without problems.
I never run with slicks though!


For 65 Mustang the smaler 9'' banjo with 28-splines will be easy to install.
Standard 8'' axle for 65 Mustang have a very thin tappered banjo.
Many of the 31-splines banjos are huge and wont fit without major machining and they are defenetly way to wide for the narrow 65 Mustangs body.

Why not buy a new 8'' 3-member for your stock 8'' from Currie? Will easy hold up for 4-500Hp

But you maybe has more serious power in mind?

<font size=-1>[ This Message was edited by: MrPer on 10/4/06 2:47am ]</font>
 

·
Registered
Joined
·
9,251 Posts
Got a friend that runs 6.80's 1/8 mile at 100+ MPH. Took him two years to break a 28 spline stock Ford axle. From looking at the failure, it developed a crack or had a fault in it already - it was not a clean break, it was actually a tear and twist as the metal came apart.

_________________

1967 Falcon 4 door w/351C - Owner built, owner abused.
70 Mustang 302 / 06 Ranger, 04 SuperCrew parts hauler
http://raceabilene.com/kelly/hotrod

<font size=-1>[ This Message was edited by: ckelly on 10/4/06 9:24pm ]</font>
 
1 - 7 of 7 Posts
Top