MuuMuu101's 68 Dart, A Learning Process...

I just reset the starter and it felt like the teeth were engaged when I installed it. It still had problems with starting up. Usually, I'd have to give the car quite a bit of gas before it would engage and start. Today was the opposite. Giving gas first did nothing but free-spin. I actually turned the key without putting my foot on the pedal and barely gave it a little gas before the car started up. So, now I feel more confident it is a starter issue. I was just thinking about getting this starter from Autozone: https://www.autozone.com/batteries-...100936_0?fromString=search&make=&model=&year=

I let the car idle, and it seemed to idle fine. I let it idle for about 15 mins and let it get up to temp. I couldn't really hear the extra noise from the engine compartment, only from underneath the car on the driver's side. So, I'm thinking it's coming from my trans? Now that I think about it, it kinda just sounds like gear noise. So, maybe it's just gear noise vibrating between the concrete floor and the unibody. You can't hear anything standing up next to the car. I only hear it when lying on the ground. Idk, what are your thoughts?