what is the 7.5 out of?

Usually no, your first going to brake axles

 

purpose was my same, how much of a whopping can a 7.5 take.... i was thinkin it cuz im might throw an 8 in and i dunt really want to change the rear end immedialty. So the question is how long before im at a light and i let go some torque and horses to the wheels and blast the hell outta that 7.5? Am i right Crebel?

 

You would be correct.

 

Then the question is do you want to be on the street when the rear end breaks and sends you into a skid and you cannot apply power to get out of the way of the semi that is screaming down on you? I have too much invested in my car and mind/body to take that chance - but to each his own.

 

OK, one more time.

It would not surprise me ifyou break the rear end the first time you get into it using the engine you have described elsewhere on the forum, in fact it would surprise me more if you don't break it the first night you drive the car if it is your desire tothrash it.

I have disassembled one of those, there aint much to them. If you were to take care of it and not thrash it from a dead stop, it would probably last for a long time, if you thrash it with a warm V-8, it will certainly break, and break damn fast.

 

I just broke my 8". I have a 408 stroker making about 400 hp and 500 lbs of torque coming from a Texasmotorsports t5. I know 8" can be built up to take alotta power, but why not save money and go bullet proof with a 9"?

 

im kinda concerned about my 8inch with my motor

i just wont get on it too much untill i can save up for a 9inch rear

 

to all the guys the 7.5 is the rear end used in the 6 banger cars same one used in the 4 banger mustang 2 and fox body not sure on anything newer then the fox body. im guessing 300 to 350hp range just depends on how well the diff is atleast change the gear oil in

 

I'm converting my '66 L6 to a 5.0 and I'm not even thinking about leaving the 7.5 in there, an 8 is going in its place. Like highhiller, I like my car too much for the rear to break and my car fly into traffic.

On another point, I consider this an accomplishment, I managed to destory a 9". It was in my '76 F150 with a slightly warmed up crate 400m, it was a lifted 4x4 with 35" super swampers on it and could do 4 wheel burnouts. I was messing around with it in the parking lot at work, doing a burnout. I heard a loud snap and then a grinding/rattling noise, I thought I broke a u joint and my reardriveshaft was spinning on the ground. Ended up being the rear, I destoryed the spider gears and ripped the splines off of the axles, they are a trophey. But thanks to the 4 wheel drive I was still in control of the truck and didn't end up on someone else's car.

So in other words the rear end snapping in traffic on the stang would be rather catastrophic, I would avoid that with upgrading the rearend.

 

Not to continue fanning the flame here, but...

When I first got my 67 about two years ago, I had no idea that I the car originally came with a 6 cylinder. (I just didn't know anything about classic mustangs, really.) Anyway, I more or less abused it for about 6 months. Mostly limited to hard accelerations and premeditated burn outs. That all ended when I discovered this board and realized I had the "small" rear end.

The end result is that the 7.5" (or is it a 7.25"?) still works great. I have a replacement 302 that is bone stock and "very tired" at best. So granted, I'm not throwing a lot at the differential - but it does still work.

Am I concerned enough to eventually replace it with an 8"? Of course. I don't like the thought of being stranded. However, with a 40 year old car - there's more reasons than I can count that could possibly leave me by the roadside. Which reminds me...I still need to get a jack for my trunk.