Break-in fluids

Breaking in that cam is the big issue on first start up.

You say the cam is used, (500 miles) by chance did you get the used lifters with it and install the lifters to the matching cam lobes they came from previously. If so the cam is already broke in to those lifters. Good to go.

If not, now you are breaking in a used cam to brand new lifters. So now you have to be extra careful breaking in that cam for the second time. Would definatly recommend using only single valve springs to get that used cam broke in again.