With a big cam, you need to see where you can get it to idle and make sure the advance doesn't kick in before that...
If I remember correctly, Eddie's 340 in his Dart liked 17° initial and 34° total... We were able to get his to idle at 800 RPM... So you may want it to be similar or a little later to kick in... The cam in his is a little milder than the 513...
My 68 340 Barracuda also liked 17° initial and 34° total with a 484/284 cam... I was able to get that one to idle at 800 RPM with Rhoades variable duration lifters... That's a bigger cam than Eddie's...
I would say to get it started first and see where he can get it to idle so you know where to set the curve to kick in... That may idle at 1000 RPM with that much cam, but can't tell for sure until you get it running...