Electrical burns maybe. That's a lot of energy that can be released nearly fully in an instant.

 

Any dangers I need to look for when buying 10000 uf 63 v capacitors?

Be sure to get them from a reputable supplier. There are too many fakes on the market.

 

The very important thing is to get the polarity correct on the capacitors. That is vital. To make them fit in the older brackets you can wrap them with masking tape to bring the diameter up to what will be held securly. That is tedious but cheap.