What Rear End Is This?

[BanditSVO]

Is this a 7.5 or a 8.8?

[PsRumors]

What's the tag say?

[BanditSVO]

what's the tag say?

265f
sl73a75 5j23

[Raven855]

Try this: http://www.mylrs.com/blogs/lrs/archi...axle-info.aspx

It's hard to say from your pic

[adamgb]

Couldn't find that number, I was thinking the l could be a 1 but still nothing. Maybe this list is incomplete.

http://www.fordification.com/rearends-ford11.htm

[adamgb]

Try this: http://www.mylrs.com/blogs/lrs/archi...axle-info.aspx

It's hard to say from your pic

hmmm according to that example it would be a 7.5. I'm 99% sure the 2 cutouts on the bottom of the cover aren't there

[BanditSVO]

Yes it appears to be a 7.5, Thanks for all the help everyone.

[Ken Potter]

The easy way to remember is the 7.5 is flat on top and bottom with rounded sides. The 8.8 is also flat on top and bottom and then flat on both sides.

[BanditSVO]

Im guessing its the stock rear and this seems to be the number

S265-F

Mustang 85-93
3.73
7.5
28

[BanditSVO]

Now that we are on topic why do svo owner switch to 8.8? Is the 7.5 really weak and know to break?

[SVOJames]

My understanding is that if you are drag racing a SVO, making decent HP with typical bolt-ons, and leave the line in the 4-5K RPM range with slicks you will most likely break 3rd gear in the tranny first.

That being said, I had a 7.5 rebuilt, and the cost was close to what Summit and others charge for a new 8.8.

My 2 cents, take it for what it's worth.

[Erics SVO]

265f
sl73a75 5j23

s is really a ?. l means "trac loc" Thus ?.73 trac loc, and the 75 means 7.5

[svono50]

Now that we are on topic why do svo owner switch to 8.8? Is the 7.5 really weak and know to break?

From what I have seen, the spider gears in the 7.5 diff will take a quick exit path when slapped with a set of slicks on the drag strip. Luckily I never had the direct experience, but I have witnessed a couple of 7.5's ventilate the diff cover.

I had purchased and installed an Auburn diff for my original 7.5 in preparation of running slicks at the track, but never got to track test it with slicks. I came across a steal of a deal on a freshly rebuilt 8.8 w/new 3.73's and picked it up. I then came across a set of low mile 4.10's, had them installed and sold the new 3.73's for 90% of the 8.8's purchase price. I then sold my original 7.5 for enough $$ to cover the 4.10's and install, so it was an almost free swap. The 8.8 held up to many slick passes w/o any issues, but I have retired from 1/4 dragging. YMMV.

[SVOeric]

My understanding is that if you are drag racing a SVO, making decent HP with typical bolt-ons, and leave the line in the 4-5K RPM range with slicks you will most likely break 3rd gear in the tranny first.

That being said, I had a 7.5 rebuilt, and the cost was close to what Summit and others charge for a new 8.8.

My 2 cents, take it for what it's worth.

the 7.5 will sure go before the tranny does....

[BlueCASVO]

the 7.5 will sure go before the tranny does....

Eric/all,

This is actually an interesting question, one I have been wondering about. The 7.5 rear is 40-50 pounds lighter than the 8.8, and I read an article in mustang monthly (archived, i was doing a search) that said the 7.5 is is a really good axle for anything but drag racing, and more than capable of handling 350hp, which is about where I want to be. Since I want to build my 85 for auto-x and road racing, why would I switch? -- unless I got a smokin deal on one Weight savings plus horsepower rating seem to make the 7.5 a better choice than the 8.8 for road racing an SVO.

I get that the 8.8 is far more common and easy to find aftermarket parts for, but the 7.5 has some parts availability.

Can you point to some tech info about the weaknesses of the 7.5? Is Mustang Monthly wrong? It wouldn't be the first time they were, but I would be interested in some tech info on it.

Thanks,