ratio411
Founding Member
That is the absolute best response to this issue I have ever read!The saying I always heard was; someone (insert name) could tear up un anvil with a Q-tip.
In it's stock form, the 8-inch rear end might take 350-400 hp, but it wasn't designed to do so. You may get away with it for some time, but sooner or later at those levels, it's time will be up.
If the factory 8-inch rears were capable of handling 400 hp, then why didn't Ford use them in the K-code 289 Mustangs or the Shelbys? The K-code was only putting out 271 hp (129 hp less than 400) and the Shelbys were only generating 306 hp (94 hp less than 400). The reason is because the Ford engineers knew the 8-inch wasn't up to the task of reliably handling the power from even a 271 or 306 hp engine.
The installation of some aftermarket 8-inch rear end parts may beef things up, but it will most likely only put the 8-inch to the level of a stock, run-of-the-mill 9-inch.
Many people want to increase the power of their engines, and usually the first line of attack is to start putting performance parts on/in their engine. Maybe I'm backwards, but I think the first place to start hopping a vehicle up should be with the brakes, suspsension, and drivetrain --then the engine.
Most early Mustang stock brakes and suspension are marginal at best with the factory-installed engines they came with. Add more power to the engine, and you are making a bad situation potentially worse. Going fast is fun. But, all the go-fast-in-the-world it isn't worth anything if you can't control the vehicle, or more importantly --STOP IT!
In the end, the arguments on the subject of 8" vs. 9" will never end. I've seen it going on for years now on the forums. Personally, since I never plan to run a factory-stock small-block, I'll continue to use 9-inch rears, because I know that it will handle any power level that I would ever attain with the engine, and not only will it handle it, it was engineered to do so.
I suppose I am one that can break an anvil with a Qtip!
I sure ain't one of the lucky ba$tards! I went to a casino last night, first time ever, and lost my a$$.
I never thought about the whole K-code analogy...
Not only did Ford NOT put an 8" behind the 271 fwhp engine (roughly 215 rwhp), but they took the time and expense to custom build a 9" that was not in inventory. They made them by grafting a 9" center into an 8" rear as a stop gap measure. Car companies just don't spend that kind of effort for no reason.
Great post.
Dave