Starter for ISX CM2250

[JimT]

Hey guys. Been getting an intermittent issue when starting the truck. It'll turn over for about 0.5-1.0 seconds then nothing for 1-2 seconds then it'll resume and start up normally. After the delay the voltage drops briefly. It's hot or miss when this happens. Truck could sit for 30 seconds or a week and it's still a 50-50 chance that this occurs or that it starts normal. Pretty sure it's the starter motor. Any thoughts?

Also, anyone know which starter (or starters) I should search for as a replacement? Quick googling it looks like delco-remy 39mt? Idk, never replaced a starter before so it's time for me to learn something new.