It would be a good idea to make sure you have enough fuel feeding at high revs. -- you probably want to break in the engine (below 5K for first 500Miles ) then get yourself to a dyno tune shop that can sense A/F ratio during the rev range -
Additionally a dyno run (runs) can tell you if your ignition system is up to snuff and if you are detonating ,pinging , or leaning out.
The rotating assembly (engine ) can take a lot of abuse and will work hard, but it needs clean
oil, good fuel and proper scaled timing and advance to work properly.
if the whole thing is OK you should be able to go to 6200-6500 but that is a lot of revs for a 347.
If it were me I would put a 6250 chip in it and make sure you have plenty of fuel at 6200 so you dont lean out up there. ---Steve