Ol' Fart's Firebird Fantasy

[oldskool]

Originally Posted by Tony Corley

If you look at the bottom of the section you quoted, it refers you to General Regulations section 2:11 You can go there and read the rest of the rules regarding rearends, Basically states welded spider gears illegal, aftermarket axles and safety retention device required anytime spool is used, regardless of ET. Also lists all classes that require aftermarket axles and retention devices..... basically anything 10.99 or quicker. Otherwise C-Clips are legal.

OK, thanks ! It appears that as long as you have any kind of posi unit, you can run even stock axles without C-clip elims, in the slower Stock classes.

2:11 REAR END
Welded spider gear rear ends prohibited in all classes. Fourwheel
drive permitted per class requirements. Aftermarket axles
and axle-retention device mandatory on Top Fuel, Funny Car,
Pro Stock, Top Alcohol Dragster, Top Alcohol Funny Car, Comp,
Super Comp, Super Gas, Super Street, and 10.99 or quicker E.T.
cars; also mandatory on any car (regardless of class or E.T.) with
a spool.

We've run low 12's and high 11's without ever breaking an axle. So do any of you guys in these slower classes run Stock C-clip axles ? Or is it better to at least buy some that are a little stronger ?

I assume that Moser axles are one of the highest priced. I see several axles that are said to be stronger than stock. So, for anybody with a low budget build, what is the cheapest good quality axles that would be plenty strong for a high 12 - low 13 sec Stocker ?

http://www.summitracing.com/parts/ms...model/firebird

http://www.summitracing.com/parts/sum-700116/overview/

Do all 8.5" ten bolt car rears have C-clip axles ? Anybody know if the 8.5 rear in a '77 Bonneville would have the same length axles as a '71-'81 F-body ? Or maybe a '73-'77 A-body ?

Some say a '77 wagon might have some odd ball rear--not an 8.5. Anybody know for sure ?

[HandOverFist]

Just my opinion, but I would not run a car with slicks without some type of axle retention. If it is a strip only vehicle I would go with a spool right from the start. I bought some 31-spline c-clip axles cheap for the Mustang, but still use a spool and c-clip eliminators.

[Rory McNeil]

Actually, Moser is one of the lowest cost aftermarket axles available. Strange Engineering is a step above, with Mark Williams at the top of the heap. Personally, I wouldn`t bother with any form of limited slip differential, a spool is lighter, stronger,and cheaper, and has NO moving parts inside to break or wear out. And stay away from "mini spools", as all the power gets driven thru the spider gears pin. I understand your budget concerns, but having to spend the money on decent components after you break the cheap stuff is not cost effective.

[oldskool]

Originally Posted by Rory McNeil

... stay away from "mini spools", as all the power gets driven thru the spider gears pin. I understand your budget concerns, but having to spend the money on decent components after you break the cheap stuff is not cost effective.

So are you saying that a high 12 or low 13sec footbraker has the power to shear the spider gear pin ?

Aprox how much ET can be gained by using a light spool rather than a posi unit ?

[Tony Corley]

Originally Posted by oldskool

So are you saying that a high 12 or low 13sec footbraker has the power to shear the spider gear pin ?

Aprox how much ET can be gained by using a light spool rather than a posi unit ?

In my experience, I usually see the carrier housing crack when using a mini spool. With spools available in the $120 range new, I agree on not using a factory carrier. And if using a mini spool, you would still have to use axle retention, so probably not much difference in price to use a spool.

[oldskool]

Originally Posted by Tony Corley

In my experience, I usually see the carrier housing crack when using a mini spool. With spools available in the $120 range new, I agree on not using a factory carrier. And if using a mini spool, you would still have to use axle retention, so probably not much difference in price to use a spool.

Mini spools still use the C-clips. So does that mean that NHRA requires elims with mini spools, even with aftermarket axles ? If so, then it appears that the only 2 logical choices are either a posi or a full spool with elims.

Since I can't install the elim kit myself, I'd come out better with a good posi and good c-clip axles. We never had any problems with stock GM posi units. But if I buy a new posi, what is the best type ? -- clutch type, Detroit locker, or ? Looks like a complete aftermarket 12 bolt is $3000 +

What ever happened to the good ole days, when I could buy a stock 3.73 posi out of a BB Chevelle for $100 and race it for 3 years + ?

[Dwight Southerland]

Originally Posted by oldskool

Mini spools still use the C-clips. So does that mean that NHRA requires elims with mini spools, even with aftermarket axles ? If so, then it appears that the only 2 logical choices are either a posi or a full spool with elims.

Correct.

[Tony Corley]

The rules say axle retention device with spool. Mini Spool is still a spool, even though it uses a stock carrier. Basically, the idea is if the rearend is fully locked, they want axle retention devices.

[Mark Yacavone]

Originally Posted by oldskool

Do all 8.5" ten bolt car rears have C-clip axles ? Anybody know if the 8.5 rear in a '77 Bonneville would have the same length axles as a '71-'81 F-body ? Or maybe a '73-'77 A-body ?

Some say a '77 wagon might have some odd ball rear--not an 8.5. Anybody know for sure ?

No. Look for mid 70's BOP mid size with 11 in. brakes.
No.
Maybe.
BOP 77 and newer wagons have a larger carrier and wider 31 spline axles (not 28)
Wagon rear is 2" wider than sedans. ( Stand back and look at the quarters.You'll see it. Made to put a 4x8 in the cargo area)
Nothing else fits them.
I know you're gonna ask if you can put a 8.5, 28 spline sedan rear in a wagon.
Technically no...because it's narrower..
With the right offset wheels? Well ,you're on your own there.

[oldskool]

Originally Posted by Mark Yacavone

No. Look for mid 70's BOP mid size with 11 in. brakes.
No.
Maybe.
BOP 77 and newer wagons have a larger carrier and wider 31 spline axles (not 28)
Wagon rear is 2" wider than sedans. ( Stand back and look at the quarters.You'll see it. Made to put a 4x8 in the cargo area)
Nothing else fits them.
I know you're gonna ask if you can put a 8.5, 28 spline sedan rear in a wagon.
Technically no...because it's narrower..
With the right offset wheels? Well ,you're on your own there.

Looks like that sorta narrows it down to a Bonnie for a '77 build.

OK, you said the odd ball rear began in '77. The '76 Lemans wagon has the same 116" wb. So does it share the same rear as any of the other '73-'77 models ? 8.5 but wider ? And if so, is there a possibility that the '76 wagon rear may have the big brakes and bolt-in axles you mentioned ?