Main Venting Location

Hi all,
New homeowner with a 1 pipe steam system. I'm pretty handy and been trying to optimize the system... Starting with venting the main whith I believe was plugged. I removed the plug on the top of the down pipe for the wet return and put on a Gorton #1 to start with (pictures attached). I don't have much space but trying to figure out if an antler with a 45° off the 3/4 port is my best bet (I have to kind of divert it a bit because it's under the joist currently. The main turns and drops down a couple of inches with elbows and then is the down pipe for the wet return. The pictures may explain this better. What are your thoughts. 

Thank you so much.