It all depends on what type shafts you are shooting and if you are using broadhead adapters etc.I shoot carbons and often use 100 gr steel adapters and put lead in the adaptor's cavity.I try to avoid heat so I tamp the lead shot in with a punch.100 gr adaptors vary and some hold more lead than others.After that,there is still a little room in the Grizzly's ferrule ahead of the adapter,for more lead.
Depending,I have gotten 28 grs of lead in a 100 gr adapter and another 23 grs ahead of the adapter.
You can gain a few more grs of weight by using tungsten putty instead of lead.I think the putty weighs maybe 10% more than lead.
If you are shooting wood,just decide how short a taper you can tolerate and experiment with one to see how much lead the broadhead ferrule will hold,ahead of the taper.
I've used woody weights on a few target arrows but don't like them on hunting arrows as it gives a second glue joint to have to deal with when aligning the tip.I just bite the bullet and buy the heavier broadheads that I need.