i keep hearing people say that the 8" won't hold up to any power. is this true? what is the weak link? i'm about to have 600 or so horses to the groung w/ slicks. any info would be helpful. thanks
The 8 won't hold up long to 600 horses and slicks, never was designed to support that much. What is your engine combination? The engine described in your signature will be nowhere near 600 horsepower without help from a Turbo, Supercharger or Nitrous. Even with help it would be tough to reach with those heads.
Yup, like he said. You'll break u-joints before you hurt the rear, if it's built and maintained right. I have a 9" in mine but only because I got a real good deal on it from a friend and it included the Trac Loc differential. If you're truly gonna have 600 hp you should consider stepping up.
9" for sure on that setup.. 600 HP with slicks? you will probably want to launch around 4k-5k rpms.. 9 for sure.. dont even try an 8"
It will support power. 350hp to rear wheels with after market axles with am auto. 300rwhp stock axles. Stick shifts drops this a fair amount. A well built 9 inch will be the ticket of you are pushing more than that or using a stick IMO.
If you have a 302 as you describe, keep the 8in and beat on it all you want. Without a turbo etc. or NOS or std. tranny sliding the foot off the clutch at launch, no problem. Stock stall converter and 3:80 gears, is not going to hurt it either. The weak link in the 8in is the size of the ring and pinion compared to the 9in, the rear pinion bearing in the case is very small compared to the "big" 9in bearing. This rear bearing takes a tremendous amount of pressur when the pinion gear is trying to climb the ring gear at launch. Axles are very minor problems up to 500 HP if using the C4 too. Of course anything mechanical can and will break if worn or setup wrong and literally beat unmercifully over time. I have stated before, that I have a narrowed 9i in my race car using "stock" 8in Maverick axles, running a 347ci, C4, 4:86 gear with full spool. If you need more gear and a real safety advantage, go for the 9in. Peace of mind, knowing you have these bigger and safer rear ends, will also be an advantage in your driving skills at the track. If your 60ft. time's are not below 1.60 seconds, you are relatively safe with the 8in you have. JMO
I have never had luck with 8" rears. I have broken them with mild 302s, auto and manuals... Never used slicks, but they broke anyway. The axles are 28 spline 9" units (in the 5 lug rear) and are not the weak spot. If you have an early case, it is weak. I used the later ribbed cases and only broke gears and differential units. So, if you have the good case, I'd have to say the diff itself and spider gears especially, are the weak parts. The ring and pinion is next. I have only broken one of those. Properly installed u-joints will outlive the rear. All of the 8" I have broken had fine u-joints that I reused later. Even the 8" 3.25:1 that I had behind a stock 460 broke without affecting joints. That one shucked the ring and pinion. Axles and case were fine. It lasted about 5 days behind the 460... and it was bone stock.
Interesting, I have run all the cases made for the 8in(which I figured was only one) with 302's, up to 351W's. 9in to 10 1/2in slicks, and never ever broke one. Course I never ran an open diff with spider gears but always figured spool's were harder on stuff anyway. Guess I was lucky those ten yrs. of hard racing. Anyone have the casting numbers of the weak 8in case? Would like to add it to my "do not use" list.
I think it might be C2OW, it is the early one with only horizontal ribs, not the later "waffle type".
this is for maverick1970. yes, that is what is in the car at the moment.it wouldn't be cool to name the things that aren't in the car yet. now, what is sitting in my garage awaiting my arrival from overseas is a roller block, procomp aluminum heads w/ 2.02's/1.60's, an s-trim vortech supercharger, parker single plane high rise manifold ( anyone heard of this company? they're from australia) and a full msd ignition system w/ boost retard. now what i don't have figured out yet is what to run on the fuel side of things. i have all the proform pieces to build the carb for it but i think i'm going to try the megasquirt system, i've been reading about it and it looks like a good system from what i've been reading. plus it is a true do-it-yourself system which is what i like about it. not too many people can say that they BUILT IT THEMSELVES. neways, sorry for getting off track there guys, so a 9" it is then. any one got one that lives in northern california for a reasonable price? thanks for the info.
haha... maybe you were lucky, with the bad luck you've had with motors over the years. Course, nothing lasts forever But I do testify to his point... he has beat the crap out of 8'' rearends over the years.
It will break at the Caps, where the small bolt for the adjuster lock goes. This is even a problem in a stock 9 inch with enough grip. Most aftermarket pumpkins have a different set up with better caps and no holes. You can break one with very little HP. if you can get the traction, Ask me how i KNOW.
