Hello, I'm trying to purchase a 3.36 or 3.23 ring and pinion (haven't decided yet) for my 68 and I was told they are hard to find because it's simply not a camaro. I'm confused because I've found some from various sources so I'm not sure if I'm missing something. Should I worry about buying from different distributors or from sellers like eBay selling a used set. Just wanna make sure I'm buying the right ring and pinion for my application how do I confirm this. Thanks.