I am running a soon to be 10 second n/a '89 firebird and am exploring the option of getting a new rear end. It is my understanding that 12 bolts and 9 inches cost about $2,000. My question is this: Can a 9 bolt hold up to 10 second runs? Also, how much would it cost to get one to that point?

 

it might, but if you've spent the time and jack on a car running 10s buying a 9" or 12 bolt shouldn't be that big of an issue. i'd get a 9" and never worry about problems with breaking rears again.

 

It depends on how hard you launch and what kind of tires you use. Too much of a sudden jolt will gernade the rearend. Running that fast on the stock 10 bolt would be a gamble.

 

I know, it sounds like a weird thing for me to not go ahead and get a 9" or a 12 bolt when I have such a quick car anyway, but I bought it like this for a really good price, is why I am wanting to keep it on a budget. Keep the posts coming! Thanks guys

 

it might iof your taking your 60's at like 1.8-1.9 anything faster will break a stock 9 bolt maybe you can get 1.7's out of a modded 9 bolt. but if you planon running slicks and dumping your clutch @ 4000rpm i'd say you'll get a 1/2 dozen runs.

 

Oh I misread what you typed. The B/W 9 bolt is supposedly stronger than the 10 bolt unit. Only problem is its hard finding a documented rating on how much TQ they can really handle. I've heard they're good up to 400 ft/lbs or so, but not really sure to be honest.

 

the 9 bolt is stronger than a 7.5" 10 bolt but the parts to fix or upgrade are alot of more. now some people think that the 10bolt 8.5" is just s strong as a 12 bolt but the ford 9" is by far the strongest of them all 9inch (ford got something right)
to be honest i wouldn't really mess around with a 9 bolt to make it withstand 10's for that kinda money a 12 bolt or a 9inch would not that much more. not including the brakes. a stock 9 bolt is a good reartill 12's. 11's are a gamble, but 10's are just a dream. imho. it also depends on what you setu up is. tellingus a na 10seccar isn't a whole lot to tell you