I know its not a Chevelle but reasonably close...I just got a 69 Impala with a stock 12 bolt. Im only looking to get it into the low 12s/high 11s on street tires. Im wanting to keep it stock appearing so it will have skinny street tires. Can I keep the stock 3.08 gear and stock axles and simply add a spool and Ford ends? With skinny street tires will the stock axles be ok or is it a grenade rearend at that point? Arent the 12 bolt axles relatively strong? I have another car with a spool so I know how it drives on street tires and Im fine with that. Will Ford ends work with the stock axles or do I have to use c-clip eliminators with them? Any recommendations for a shop to do this work in eastern PA or in NJ? Thanks!!

I know its not a Chevelle but reasonably close...I just got a 69 Impala with a stock 12 bolt. Im only looking to get it into the low 12s/high 11s on street tires. Im wanting to keep it stock appearing so it will have skinny street tires. Can I keep the stock 3.08 gear and stock axles and simply add a spool and Ford ends? With skinny street tires will the stock axles be ok or is it a grenade rearend at that point? Arent the 12 bolt axles relatively strong? I have another car with a spool so I know how it drives on street tires and Im fine with that. Will Ford ends work with the stock axles or do I have to use c-clip eliminators with them? Any recommendations for a shop to do this work in eastern PA or in NJ? Thanks!!
for what you intend to do the stock axles whould be fine,
with the 3.08 gear i suspect you will need to use some nos or have a low geared transmission :)

The stock axles will not work with the Ford axle bearings.

Using a spool on the street is dangerous. A spool puts too much stress on wheels, axle studa and axles. It causes parts to break and cause you ti kill someone when a wheel comes off. It might not have happened to you yet, but it could. I have seen these parts break several times. This is not a rumor, it's a fact. If you will be running on the street

You are going to need more than the 3.08 gear to get that heavy car moving.

What about a lock-right or are those the same? I figured axles would be safe with Ford ends or c-clips, didnt think of studs. Even with skinny street tires the studs are a weak spot?

What about a lock-right or are those the same? I figured axles would be safe with Ford ends or c-clips, didnt think of studs. Even with skinny street tires the studs are a weak spot?

Even with skinny street tires, other stuff can break... I have broken 12-bolt axles and gears in small block cars without much traction. I even broke an axle behind a 307/powerglide combo. That car did NOT have enough power to even spin a single tire, yet the axle still broke...

This is one reason why spools aren't good, unless you have C-clip eliminators...

12-bolt axles are "relatively" strong, but they are still 40 years old (metal fatigue), and they are production items that could easily have flaws, etc... They might be fine, but they might break with the power you will need...

You should be able to buy good replacement axles for about $200+ a set, and them maybe run the lock-right. And then you can also upgrade the studs at the same time... IIRC, the lock-right still allows "differential" action to occur, just not smooth like a clutch-type limited slip setup...

The Lock Right isn't going to be as strong as other differentials, but it's better than trying to run a spool on the street. I've got a Lock Right in my truck and I've put over 130,000 miles on it with no problems. I don't drag race the truck.

I also recommend a new set of axles. The after market axles are about 30% stronger than stock. Moser and Yukon are good axles. I've not had any problems with either one.