Barracuda won't roll

Thanks for the great advice.
The replacement seal I have is about 1/16" larger than the pinion bore. The bore is 2 1/2" inside diameter. The new seal is 2 9/16" o.d. When I hold the seal up to the differential it's obvious it won 't just "tap in"
The seal will have to be distorted to be installed. Does this seem right? I know I ordered the right part.