Rebuilt engine initial fiasco

Engine might be fine, once you get oil filter problem solved. When we did the upper end of 273, it took us quire a bit to get it started. Once srarted we continued with normal break-in and everything is/was fine. 15, 000 miles ago and no issues. Comp Cam and lifters.
Good luck

YOU dodged a bullet. This has killed many cams as of late. If the OP got a quick fire up and continues the break in process when the oil filter issue is solved, he'd likely be ok, but I've seen more than one Comp Cam go flat when the motor doesn't fire immediately. That's why I'm a roller cam man now.