I have an 850 gallon 112" tall vertical air receiver tank that has 1" bungs. 1 on the very top dome I intend to use for air separation, 2 are at the top seam, (approximately 10" down from top of dome), 180 degrees from each other, I will use 1 for boiler loop and the other to feed the house. The one thats about 10 inches up from the bottom dome I plan to use for return from the house, and the 1 on the bottom dome for boiler loop return. Have been told that I can use 1 1/4" black pipe for the boiler loop and just neck it down at the tank, and would be just fine for flow and autosiphon. My question is, will this work properly, or should I grind the bungs off and install 1 1/4"s. Hate to monkey with the integrity of the tank if I don't have to! For comparison 1" black pipe is 1.049" ID, and 1 1/4" is 1.380" ID. Also have to make sure that necking the lines down won't hinder moving all the heat from my EKO 40. What do ya think?