Just an opinion question: I am building a 427 from the ground up (wanting to achieve around 500 at wheels, maybe a little less). I am also going to have to build the entire rearend because it definately won't hold up to the new engine. Which first? It is a 71 Camaro, basically stock.

 

IMO-Start with the engine. Once you know how strong the engine is, you'll know how much to beef up the rear. The alternative would be to just go all out and bulletproof the rear-big(ger)$$'s.

 

It's really up to you. If it were me, I'd start with the rear end. If it's a stock 10-bolt, it'll be toast quick with 500 hp turning it. I've done it both ways and only did the engine first once. Nothing worse than just starting to have fun with your new motor and having something break. Then you get to wait until you get it fixed right, to have fun again. If it were me, I'd sell the rear (ebay should net some decent money for someone who needs the complete rear) and use that money to start in on a 12 bolt or a nine inch. Do it right the first time, and all you have to worry about is changing the fluid.

 

Im not sure what rear is in that car. If is the 8.5 rear it is going to be pretty tough to begin with. If its the 8.2... its not going to live long.

http://www.novaresource.org/axle.htm

 

Ray, what gears you running? 4.10's?

 

Stock 71 gear ratios


Manuals;

Base 307/250 = 2:95
L-65 = 3:08
L-48 = 3:42
Z-28 = 3:73
LS-3 = 3:42


Autos;

Base 307/250 = 3:08
L-65 = 2:73
L-48 = 3:08
Z-28 = 3:73
LS-3 = 3:42

 

Hey Scott,

4.56's are in the car now. She really screams at 55. I have a set of 4:10's. Im thinking of putting in and going with a shorter tire to help make up a little bit of the difference. It may even pick up some ET on the bottle with a less gear.

Ray

PS.. I like the wheels you picked out. Should look NICE on the old 69er.

PPSS ..Scott and I were talking about getting together after Christmas to check out the video from Byron of the wheelstanders. You should come over and check it out with us.

 

4.56's? Damn, no wonder that thing is so quick on the street.

I'm all for the video. Keep me posted. BTW, I picked up a MiniDV camera, and I can use it as a pass-through video capture device, so I can convert any of those videos the Don, Scott, etc have into mpg's so we can post them on the internet.

Ok, back to the thread about 10 bolt rears. Sorry guys.

 

I'd do the rear end first and make it bullet proof. Might as well get that out of the way.

 

1970 was the last year for the weaker 8.2" or whatever it was rearend. In 1970 the 12 bolt came in Z28 and SS cars only. BUT from 71 thru 81 the ONLY rearend you could get was the 8.5" 10 bolt which is just as strong as a 12 bolt is. There is much written on this subject but the short version is the first weak link in the 8.5" 10 bolt AND the 12 bolt is the axles. especially if its in a manual trans car with slicks . There guys running 8's on upgraded 10 bolts. heck , there are guys running 10's on stock axles but I dont recomend it.

Doug

 

From what Dougj said yor car has the 8.5 10 bolt. That rear is VERY strong even in stock form. With a set of good axles your pretty well set for a hot street car.

Kurt Urban used to un an 8.5 in a SS car in the NSCA. Low 9's I believe.

 

so basicly.... start with the engine.

 

Well I Hvae Seen Some 7.5 inch rear end's hold some awsome engine's.

Me and My cousin Built an 86 S-10 with a 450hp 406 4bbl 2 bolt main, 700r4 stage 1 sjift kit pluse filter kit shift improover,and 4.56 gear's with 235/70R15 Pursuite Radail's .

it has a 7.5 inch 10 bolt rear and it;s been going for almost 7 year's now.

you should see the people who try and race it we left the
" 2.8L" emblem's on it.
it's kinda Rusty now.
So it look's like a v-6 Heap but you wouldn't bleive the LS-1's it will walk all over street racing.

but your going with a 427BBC so i'd prolly upDate to a 8.5 inch 10 bolter atleast.......

But I'd Run a Dana/AMC 20 Rear end are awsome IMO.

 

u can end up spending thounsands of dollars on a rearend and not even realize it till ur ready to start building a motor...

so ur rearend is a 8.5" good... start with the motor then.

 

Yea i agree the 10Bolt 8.5" rear end is plenty stronge for a 427BBC.
Rebuilt 8.5" rear end should hold fine with a 3.55 or 3.73 gear's.
it's a big block so if yiu went 4.11's you;'d be ok but 4.56's in a street Big Block sound's kinda risky.
you'll have about 530Hp hitting that rear end ,with 4.56 gear's you'll be working it rather hard but with good axles and all New bearing's , and an 85w-140 gear Lube you'll be plenty fine.Every couple of run's I's Pull the Rear Cover off and check for Shaving's in the gear lube. If after Brake in there is no shaving's you should be fine.