I did the sohc to dohc swap about 300 miles ago, The car has been running real good too. I changed my oil yesterday, when I put the oil cap back on it broke. As in the cap can just spin freely without any clicking. It doesn't come off either. Can this cause any problems?

My reason for asking is, after that I drove the car for about 10 miles and it developed a slight jerking. And now it jerks all the time. It feels kinda like it isn't getting enough gas. It idles fine but it does kinda "spit" out the exhaust. It does kinda smoke but it is also like 20 degrees out, I don't think smoke has any color to it other then white.

No codes either it is mopar performance computer too but i dont think that matters.
I plan on taking a look at in the morning.
what all should i look at?

 

You need to make sure the oil cap is tightly sealed. If not the car will run weird, sound weird, and could cause harm. The heat coming from that hole can melt the material on your hood.