I use Valvoline 5x20 wt. as my break in oil on street only builds, I will change it and the oil filter on flat tappet cam motors after breaking in the cam and cut the oil filter apart to inspect what was trap in it to make sure the cam is not losing a lobe or two
On roller cam motors it depends on what the motor will be used for, street only gets the same Valvoline 5W20WT. oil street and strip motors and race only motors get Valvoline VR1 10x30 wt. oil
No synthetics oils for me yet Maybe soon
The main reason for me not using any brand or weight synthetic is they will leak when regular petroleum base oils do