I am remodeling a kitchen in my one story home. I currently have a 1 1/2" secondary vent pipe comming up out of a utility wall behind the sink/dishwasher area, then up through the roof. I would like to position a window above the utility wall. My using an in-line vent was suggested as a means of shortening the existing vent pipe. My question is, will the plumbing work alright if I cut the vent pipe and apply an in-line vent at 43" from floor. The tallest drain in the house is a washing machine drain that is 38" off the floor down-stream in the system. The in-line vent would be enclosed inside the utility wall, which I realize would be a problem if it overflowed. The washing machine does cause a temporary back-up into the kitchen sink on initial drain surge, which I would also like to prevent. The hight of the water level due to this back-up is never greater than 2" inside the sink, making it about 31" off the floor. Your comments and/or suggestions please.