What's the maximum imbue point with overcharge on 99qua and Masterpiece armor/weapon?

According to this site, the max overcharge is 5 points.
http://daocinfo.awardspace.com/guides/c ... _table.htm

And cccording to kort v1.45,
- Max for 99qual is 33.5
- Max for MP is 37.5

So is it 5 points overcharge or 5.5 points?

If I decide to go with 5.5 points overcharge and I use all 99% gems. what's the percentage of explosion on 99qua armor/weapon if you do 33.5/28? What's the percentage of explosion on 100qua (MP) armor/weapon if you do 37.5/28?

99% quality base imbue is 28. 5.5 OC makes it 33.5.
MP quality base imbue is 32. 5.5 OC makes it 37.5

with 4 99% quality gems the explosion chance on a 99% item is 1%
with 4 99% quality gems the explosion chance on an MP item is 0%