8.8 Rear-end

GodStang · 06-29-2002, 12:26 PM

I am looking to switch from a 7.5 to an 8.8" rear end. What is the difference between 28 spline and 31 spline. Which is better why is it better and is it worth it.

sn95gt19 · 06-29-2002, 12:49 PM

if you have a 7.5 im guessing you have a 6cylinder. (unless its older) the only time your gonna need 31 spline axles is if your putting some decent power to the ground, the 31's are just a stronger axle to handle more power.

sn95gt19 · 06-29-2002, 12:50 PM

sorry didnt read that you had a 94 V6, my fault

Agent_4573 · 06-29-2002, 12:52 PM

Unless your putting down in excess of 340 horsepower daily, you probably won't need the 31 spline axle. I mean its a stronger axle, but with a v6 you probably won't need that much strength anytime soon.

GodStang · 06-29-2002, 01:24 PM

I am setting my V-6 up to drop a 351W into it. Most likly blown.

Mr 5 0 · 06-29-2002, 01:56 PM

A 31-spline diff/axle combo is stronger than a 28, obviously, but only worth the extra money if you need it.

If you're dropping in a blown 351 and are swapping out the rear anyway, go with the 31-spline set-up. You'll need it, especially if you run slicks.

PKRWUD · 06-29-2002, 02:22 PM

Exactly. If those are your plans, definately go for 31 spline axles!

Take care,
-Chris

Ieatcamaros · 06-29-2002, 05:09 PM

I'm sorry, but I just do not understand this. Are the 31 splines and the 28 splines the same size diameter? This is the only benefit I can see from this. I mean if they are the same dia. then I can't see the benefit. If you put 31 splines on the same size dia. of the 28's then there will be more splines, but they will not be cut as deep into the axle shaft. On the other hand, you will have more splines to grip with. Theoretically speaking, shallow splines are easier to strip off. The deeper cut splines are easier to snap. So my question is: Is that what drag racers want, to strip the spines rather than to break them? Or is there something that I am just missing here?

PKRWUD · 06-29-2002, 05:26 PM

More splines = larger diameter = stronger axle.

Take care,
-Chris

Ieatcamaros · 06-29-2002, 06:14 PM

Ok, the 31 splines are larger dia. axles. Now I get the point. How much bigger are they. 1/4 inch?

PKRWUD · 06-29-2002, 09:45 PM

The 28 spline is 1.2" in diameter, and the 31 spline is 1.325" in diameter.

Take care,
-Chris

tarmon8r · 07-01-2002, 09:31 PM

so bigger is better in this case right PKRWUD

LOL

PKRWUD · 07-01-2002, 11:27 PM

You betcha!

Take care,
-Chris

06-29-2002, 12:26 PM	#1
GodStang College Stanger Join Date: May 1999 Location: Aiken,south carolina, usa Posts: 1,097	8.8 Rear-end I am looking to switch from a 7.5 to an 8.8" rear end. What is the difference between 28 spline and 31 spline. Which is better why is it better and is it worth it. __________________ 2003 Sonic Blue Cobra

06-29-2002, 12:49 PM	#2
sn95gt19 motors done......woohooo Join Date: Mar 2002 Posts: 799	if you have a 7.5 im guessing you have a 6cylinder. (unless its older) the only time your gonna need 31 spline axles is if your putting some decent power to the ground, the 31's are just a stronger axle to handle more power. __________________ 95gt lazer red (98 cobra clone) Rice Haters Club Member #116

06-29-2002, 12:50 PM	#3
sn95gt19 motors done......woohooo Join Date: Mar 2002 Posts: 799	sorry didnt read that you had a 94 V6, my fault __________________ 95gt lazer red (98 cobra clone) Rice Haters Club Member #116

06-29-2002, 12:52 PM	#4
Agent_4573 Registered Member Join Date: May 2002 Location: New Jersey Posts: 375	Unless your putting down in excess of 340 horsepower daily, you probably won't need the 31 spline axle. I mean its a stronger axle, but with a v6 you probably won't need that much strength anytime soon. __________________ '89 LX 5.0, off-road h pipe, flowmaster muffs, underdrive pulleys, rebuilt WC T-5, King Cobra Clutch, 65mm throttle body, Explorer Upper/GT40 lower, Lakewood Rear Lift Bars. 76mm C&L Mass air w/ inlet pipe, Twisted wedge heads w/ stage 2 port,polish, MAC equal length shorties, Billet AFPR, 255LPH fuel pump, fresh low end w/ 10.5:1 compression. If anyone ever wants to go to Raceway Park in Englishtown New Jersey, give me a shout. RICER HATERS CLUB MEMBER 87! www.ricehatersclub.com

06-29-2002, 01:24 PM	#5
GodStang College Stanger Join Date: May 1999 Location: Aiken,south carolina, usa Posts: 1,097	I am setting my V-6 up to drop a 351W into it. Most likly blown. __________________ 2003 Sonic Blue Cobra

06-29-2002, 01:56 PM	#6
Mr 5 0 Conservative Individualist Join Date: May 1997 Location: Wherever I need to be Posts: 7,487	31 vs 28 A 31-spline diff/axle combo is stronger than a 28, obviously, but only worth the extra money if you need it. If you're dropping in a blown 351 and are swapping out the rear anyway, go with the 31-spline set-up. You'll need it, especially if you run slicks.

06-29-2002, 02:22 PM	#7
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Exactly. If those are your plans, definately go for 31 spline axles! Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

06-29-2002, 05:09 PM	#8
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	I'm sorry, but I just do not understand this. Are the 31 splines and the 28 splines the same size diameter? This is the only benefit I can see from this. I mean if they are the same dia. then I can't see the benefit. If you put 31 splines on the same size dia. of the 28's then there will be more splines, but they will not be cut as deep into the axle shaft. On the other hand, you will have more splines to grip with. Theoretically speaking, shallow splines are easier to strip off. The deeper cut splines are easier to snap. So my question is: Is that what drag racers want, to strip the spines rather than to break them? Or is there something that I am just missing here? __________________ The sig says it all.

06-29-2002, 05:26 PM	#9
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	More splines = larger diameter = stronger axle. Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

06-29-2002, 06:14 PM	#10
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	Ok, the 31 splines are larger dia. axles. Now I get the point. How much bigger are they. 1/4 inch? __________________ The sig says it all.

06-29-2002, 09:45 PM	#11
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	The 28 spline is 1.2" in diameter, and the 31 spline is 1.325" in diameter. Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

07-01-2002, 09:31 PM	#12
tarmon8r Registered Member Join Date: Jun 2002 Location: manassas, va Posts: 186	so bigger is better in this case right PKRWUD LOL

07-01-2002, 11:27 PM	#13
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	You betcha! Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

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