You can always add more chain to get the length you need. You just want to make sure it is as long as possible. Say the chain is only six feet...you can only lift the animal 6', then you will have to tie him off and rehook. A lot of work. I would suggest getting a chain hoist that has a lot of chain and is not restricted to a set length. I have a chain rachet hoist. I don't know the correct term so I'll just stick with that one. A friend had one in his garage that we used to hang an elk with. I started looking for one. I happen to be in a second hand junk store one day and found one for $35...mine! I carry it with me when I hit the woods.

The other thing you need to do is to make sure your rafters are BEEFED up enough to hold the weight of whatever animal you are going to hang. Rafters are not designed for that kind of downward pressure. Either run some 2x8/10/12 nailed together across several rafters on end and/or have some posts you can put under the rafters to support them all the way to the floor. Good rule of thumb is...do what you think would hold...and double it.

Good Luck
Reid