It is mounted to the body just above the rear axle. I was going to get the 4070 as you are, but I was somewhat confused about the 4-6psi rating on it compared to just 4psi on the other Carter pump. Judging by the different size/shape of the 4070, you could probably mount it on the actual frame rail which would be a better spot. The body metal is a bit thin although it looks to be sufficient.

I'll get a few more pics in the next day or so depending on weather.

I don't know if your pump comes with a filter, but it definitely needs one between the tank and pump. The instructions with mine stated the warranty would be void if there was no filter installed.

I forgot to mention I basically followed the fuel lines back to the tank to route the power wire.