In preparation for new large bath tub I'm looking to replace my 40 gal gas water heater with the 75-gal kenmore model (33176). I have a venting concern as the upper edge of my vent pipe enters the Chimney at a height of 63". The heater is in basement (large unconfined room) 4.5 ft from 100-year old chimney. Specs state model 33176 has total height of 62.25" with diverter, tank height 59".
Does the "diverter" include an elbow? Concerned that I will be unable to get 1/4" rise per foot on the vent pipe leading to chimney. Ideas? Are there exhaust blowers available to assist in creating the draw out the chimney? Is there any 75-80 gal gas model available that is shorter? Will I need to buy two 40-gal and plumb them in series to get the vent elevation lower?