I have a section of soil stack in my basement running horizontally to an existing toilet in the basement (the horizontal is linked to a vertical stack from the second floor). I'm going to remove that basement toilet and use the soil stack connection for a new toilet I've installed on the first floor of the house. Question: the new toilet on the first floor is 8' above and 6' across from the soil stack connection in the basement. Is it better to have the new PVC waste pipe from upstairs go straight down first, and then slope to the existing connection, or better to have the pipe slope from the closet bend and then make a vertical drop right before the soil stack connection? Thanks for any advice.