Where to Drill Holes Keggles,MLT,HLT?

I'm working on building an e-herms and wanted to know where to place fittings. I have a guy that's going to weld the fittings on the 3 kegs that I have. I'm going to do bottom drains. But how high up from the bottom do you put the element on the keggle and HLT? How far from the top do you put your top fitting on all three vessels? Where to put the fitting for the coil on the HLT?

Is there any spec plans out there that give these measurements?

Am I missing any fittings?

For the kettle, you need to put the heating element as low as possible. Even with that, I still need 3 or 4 gallons to cover my elements. I also put my side port as low as possible. I use it as a back up drain and have no issues whirlpooling, but most people go higher. If you are going to have a temperature probe and/or sight glass you'll want another port.

Part of the answers depend on whether you are going to be doing 5 or 10 gallon batches, or both. I kept my return ports and temp sensors low so I can do 5 Gallon batches.

Going to be doing both 5 and 10 gallon batches.

One thing to keep in mind is do not put fittings, especially for the thermometers directly over the vents from the bottom of the keg to the side. The builder/former owner of mine did that (on all three kegs). I have to try to remember to to stuff a piece of aluminum foil in there so the direct heat of the flame doesn't mess up my thermometers. Also (I believe), the vents at the top line up with the bottom, so if you have a boil over, it would all run down the side to the thermometer.

And be sure drill holes in the bottom rim in three or four places for safety so the hot air can vent and it doesn't explode.

https://www.homebrewtalk.com/showthread.php?t=41422