Starter Problems

Hey all. My starter seems done for. It will still kick in if I'm holding the ignition and give it a tap with a wrench, but I need a new one. Problem is there are two to choose from, an 8 teeth starter and a 10 teeth starter. I'd rather not have to take off the old starter until the new one is here and ready to be put on because this is my daily driver. Anybody know which starter I need, or will I have to figure it out for myself?

It's a 1992 B2200, petrol

The starters for automatics and manual transmissions are different. Does that help?

I have a manual. The guy at the spare parts store here told me that the 8 teeth one would work for both...but I don't like the sound of that. So, I bought both of them and he said I can return the one that I don't use. I'll let you know which one it takes once I get the b*stard off tonight. Borrowing an impact gun from a buddy, because those nuts won't budge. Hoping I don't break off the bolt!!