I got the truck back on the road saturday and have been driving it back and forth to work since. Well saturday morning until this morning when I've been going 70mph the rpm would be around 3000. But this evening coming home it was around 2000? That's great for my fuel consumption, but is everything else alright???

 

If nothing sounds or feels broke, I wouldn't worry. Maybe it was cooler out and the wind was pushing you instead of being a resistance so the truck wasn't trying so hard lol

 

Went back out to the store and right close to home I hear something weird coming from the front left tire. I get home and look behind it to find the cv joint had broken, can I still drive it? I've only got one day until the car part comes in and I can start driving that again.

 

You could like you just were lol but no, it is definitely not a good idea. Don't wanna cause any further damage. So let it sit for a day til you get the new part.