I've seen an L riding on 22s, but it didn't look like you would be able to drop much after that. I say that because it looked like the rims would hit in the wheelwells after putting 22s on. IMO you would be able to drop the back around 2" to level it with the front.
Front probably wouldn't go down very much without hitting.
2/4 drop is the safest drop. 3/5 is probably as much as you can go. But I am going to do a 2/4. I have a 0/2 drop right now. Waiting on rear hangers before I install my 2 inch drop springs. To give me the 2/4 drop.