65 Mustang with 289, 4 spd manual T-10 trans. Replaced clutch last year when I first got the car. Also put a clutch return spring in to assist in the return of the fork. This morning when I drove the car it had a hard time going into first and staying in all gears but 4th. 1. I think I may have got the wrong clutch from O'Reilly's. 2. How do I make sure that I'm putting the right clutch in? There are a couple of options at the auto store. 3. The fork seems to have been cut/modified to fit in between the trans and the exhaust. Do I have the wrong fork? 4. I had the return spring attached to the fork and then to a cut hole in the frame. I'm assuming this is in the wrong place. The reason I did this was because the the fork and bearing would not return to the correct position after engaging the clutch. Any advice/help is always greatly appreciated. I'll continue to research as well. Still learning.