8 inch rear with 31 spline axles

[TOM B]

Over the weekend on one of the car shows on the tube was a 8 inch rear they built with 31 spline axles. They done this to save on the weight and said it would hold up to every STREET application but slicks, sounds cool but I missed most of it.

 

[brianj5600]

I would be careful listening to TV shows. Most are not done by car guys. Some of the people on camera don't even change their own oil. The script writers are not car guys either. They mess up facts so much it is not funny. I would just watch for entertainment and get tech elsewhere.

 

[12sec67]

very good point Brian especially listing to that guy

 

[bnickel]

it was in a special on Mustangs for the show Chop Cut Rebuild and the shop doing the work was Autoworks Intl. and the car was their Phantom DSC Mustang that was built for Dynacorn using one of their new bodies and for clarification the intended application was for small displacement engines under 400hp, like the 345hp Ford Racing 302 they were using.

i've said the exact same thing myslef before many times. an 8" rear that has been upgraded with a good diff and 31 spline axles should have no problem handling that kind of power in small displacement engines like a 302 provided you aren't launching the car on slicks. does that mean i'll be giving up the 9" in my cougar behind my stock 351w? hell no, but i wouldn't concerned with upgrading to a 9" if the cougar had come with a 302 and 8" rear either, i'd just use a detroit true-trac and 31 spline axles if i planned to stay under 400hp.

 

[Stanger007]

The pinion support in the case is what normally cracks in the 8". It is just not beefy enough.

Wes

 

[Decurion]

A friend of mine just blew up his 8" last week. 3300lb car, ~375hp, 5 spd, 235 drag radials.

 

[bnickel]

let's see here....sticky drag tires and a manual trans. those are the 2 key ingredients right there. do you happen to know if it was a pre 67 case or a later one?

 

[mdjay]

Just ditch the 8" Hey that rhymed...

 

[Decurion]

bnickel, its an original v8 63 falcon sprint, but for some reason I remember him mentioning it had a later case, but Im not sure.