* Budget: Prices range dramatically from rebuilt stock units to high-performance aftermarket differentials.
* Intended Use: Street driving? Drag racing? Autocrossing? Road racing? This heavily influences the ideal gear ratio and overall strength.
* Power Level: How much horsepower and torque will your 305 (or future engine) be producing? A stronger rear end is needed for higher power levels.
Options, ranked roughly from least to most expensive and performance-oriented:
1. Rebuilt Stock 10-bolt: This is the cheapest option. You can find rebuilt 10-bolt rearends relatively easily and inexpensively. However, they have limitations in strength, especially under high horsepower. A good option if you're staying mostly stock. You can change gear ratios within this upgrade.
2. Upgraded 10-bolt: This involves using stronger axles, a better carrier (like a posi-traction differential), and potentially upgraded bearings within the existing 10-bolt housing. This improves strength and handling significantly over a stock rebuild, but it still has limits on how much power it can handle before breaking.
3. 12-bolt conversion: A 12-bolt rear end from a larger or higher performance GM vehicle (like a Chevelle or early Camaro) is a significant upgrade in strength and durability. This is a more involved swap requiring fabrication and modification, but it's a very popular choice for higher horsepower applications.
4. Aftermarket 9-inch Ford conversion: This involves a complete swap to a Ford 9-inch rear end, which is known for its incredible strength and versatility. It is an extremely robust and popular choice, but also the most expensive and labor-intensive option.
Gear Ratio Considerations:
The gear ratio you choose is critical and depends heavily on your intended use and tire size.
* Lower gears (e.g., 3.73, 4.10): Better for acceleration, but lower top speed and higher RPMs at highway speeds. Ideal for drag racing or spirited street driving.
* Higher gears (e.g., 2.73, 3.08): Better for fuel economy and higher top speed, but less acceleration. Better for highway cruising.
In short: For a mostly stock '92 Camaro RS 305 with mild performance modifications, a rebuilt stock 10-bolt with a suitable gear ratio is a cost-effective choice. If you plan on significant power increases or serious performance driving, a 12-bolt conversion or a 9-inch Ford swap are much stronger and more reliable options. Talk to a professional shop specializing in GM muscle cars for advice tailored to your specific needs and budget.
