take it easy dont beat on it!if someone has put any new internals in it, they need to wear down. there are usually paper work that comes with the new internals to what you need to do. if you dont have any paper work, try to contact the company.
if i were in your sistuation and could not find any paper work on it, then this is what i would do. i would get the engine running and let it idle for about 20 mins around 1500 to 2000 rpms. then i would take it real easy for the next 100 to 200 miles. then i would vary the rpm range, but dont go all out. around 200 - 300 miles i would do an oil/filter change. check the oil after you dump it to make sure you dont have an extreme amount of metal flake in it. you will have alittle bit. also check fluid levels alot, during your break in process. also watch your gauges closely. i have never owned a neon, nor worked on one. but this is pretty much what i do on every rebuild.
edit: make sure you do turn it over a few times with distributor unplugged, to be sure oil is everywhere. i would pull of the valve cover and watch that oil is getting to the head.