Flywheel ring gear.....

[41panelmark]

Guys, I am guessing that the ring gear on a stock flat head is the same size for all correct? I have a flywheel with bad teeth on that gear and would like to have it replaced. What is the best method for replacing one or who should do it, i.e., machine shop?

I see that places like Mac's carry them, which company has the best and or correct part?

thanks.