the plastic one on the output shaft was junk

 

Gonna have to change that one too then...... I don't think its too much of an ordeal......

 

if i cant find the gears with the same teeth can i change both as long as they still line up?

 

Tooth count is how the speedo is calibrated. If you have larger than stock tires, or are going to change gears in the diffs, NOW is the time to get the right ones for that exercise. I think further down the page that I linked to earlier, or, from a link on that page, there is a chart that goes by tire size, and gear ratio, so you can get the right combination for your application.