Another 8" rear question

I'm no expert but I'm pretty sure your cobra has an 8.8 and is pretty stout in its own right. If I'm right the 8.8 is stronger than your 8 but not as strong as a 9. I think the 8 will hold up to 350hp with out slicks. Hope this helps.

My experience with a 351 and an 8" isn't great. I ate two of them with a 2-barrel Windsor in my '66 as a teenager. I will say this much however, built properly, the 8" can handle anything your engine can put to it. It's the side load spider gears that give out. In the case of a high output application with a strong enough diff, the axles get munched. The only option to remedy that is stronger 28-spline axles because as of my last research, they didn't make differential options that would allow for more splines.

stock for stock the 8.8 in the cobra mustang will handle large amounts of hp, nearly as much as a 9" will. in fact i have seen 10sec mustangs running the stock 8.8 rear, and many mustangs with a slightly modded 8.8(better axles and a proper rear diff cover that supports the bearing caps) going deep into the 9 sec bracket. the 8" rear stock will handle about 350 with slicks, for a time, and around 375-400 on street tires, again for a time. with a few mods, the 8" can handle more than that. the biggest problem is th axles are only 28 spline axles, and the diff(stock) is kind of weak.

the 8.8 is a very strong piece, the only thing that makes it better is removing the c clips with c clip eliminators much like the standard 8" and 9" have. the 8" doesnt have c clips so at least if you break an axle, your rear end wont go falling apart on you i know ive thrown 450 hp and 480 ft lbs of torque through a stock 3.27 posi 8.8 on my 94 supercharged cobra w/ drag radials and it didnt flinch. i dont think id want to do that to my 65's 8", although it works great for my mildly modded 289. u can make the 8" stronger like others have said. i replaced my 8" with a later style ribbed case, with an auburn posi and new parts including a new ring gear. this strengthens it a little bit.

8" rear end

I have had a 8" Trac-Loc in my car for the past 6-7 years. It has a ribbed case which I thinks helps a bit. Engine has been a beefed up 351C all this time and I drive it pretty hard. Have never had any problems, but I have a 9" waiting in the wings.