Need help with tub faucet

[mgen]

I need some advice on the best way to install my free standing tub faucet. I guess it's called the "traditional clawfoot" type? The one that has two separate posts for hot and cold. Unfortunately, I think it's sort of cheap and the direction really suck. My problem is that I noticed that the threads at the bottom of each supply post are only about an inch long and my subfloor is 3/4 which means only a very few threads extrude through the bottom of the floor. I was assuming that there would be faucet lock nuts that came with it to screw on underneath the floor to keep them tight but of course it didn't come with them. As I'm thinking about it, I need to have a washer at the top to keep the post from sliding through the hole in the subfloor and then have something on the bottom to keep it tight. However, like I said, there's no room for lock nuts and the water feed line. I've tested it with a scrap piece of subfloor to see if I could come up with a combination that would work and I found that I could get a washer at the top and bottom and screw the braided supply line on and it would be nice and snug but I don't like the idea of using the supply line as the tensioner as opposed to a separate nut. Hopefully, this paints a good enough picture of my problem. Trying to figure out another way to secure it without the possibility of leaking. Thanks in advance.