Is it okay to replace mineral oil/ break in with Synthetic after say 500 Miles?

I got the engine rebuild done on my '78 van. It has a mopar LA 318.

I honed the cylinders and reringed it along with upgraded heads and cam.

I hag success with the initial fire up / cam run in. No wiped lobes that I can tell.  

After light 'round town driving for ~500miles I wanted to change the oil. Is it okay to switch to full synthetic at this point?

Thanks Sages,

Greg

I would run it with conventional oil again at least for one more oil change. Switching to fully synthetic too early on a rebuilt engine is likely to extend the time it takes to properly break in. 

Ya, I too would stick with conv oil for at least a 1000 miles. This will, imo, give the piston rings time seat in. That said, this can be very controversial topic.

I think your biggest hurtle is the cam and you seem to have got past that.  I would be more interested in what the cam needs for zink in the oil moving forward for the long term. Another 500-1000 miles on non synthetic oil won't hurt anything but I would want to know what the cam manufacturer wants you to do. 
 

The funny part is when I was big into building 4age motors we would just use the synthetic oil we were going to run the motor on from the get go. I think we were using redline at the time.  The motors were race motors so they got a 15-20 min run in in the car an oil change and then off to the track to be flogged as usual. Never had an issue. We were in most cases re using cams that were matched to the lifters so we were only really worried about bearing clearances and rings seating in the bores.
 

One of the biggest engine builders in the area told me that ring seal occurred in the first couple minutes of the motor running and what oil you use has little to no effect on it. If you do encounter a ring seal issue on a rebuild it is not the oil you used it is an error that was made by the builder.   Ring gap and putting a ring in upside down are the big ones. The other problem is cracking a ring when installing the pistons. People will blame the oil but in reality other than using a high zink oil recommended by a cam shaft manufacturer for initial start up and for a specific amount of time to set the cam surfaces just about every other issue on a startup is builder error and not a type of oil problem.  

Agree

Thanks all.

Just drove about 250 miles to Tallmadge and back last night. I know no rings got cracked or were put in upside down.  Used plenty of break in additive and proper lube on the cam and lifters. 

Will change oil using mineral oil after first 500 then synthetic on the oil change after that.

Cheers!  Greg