end of main vent(s)

Luv'nsteam

Once I figure out how much venting I need, where is the best place to put them- at the end of the main (top-left) before the first "T"  or near the end of the dry return (the short nipple below the "T's")?  Keep in mind, it appears I will be completely dissembling what you see and redoing it in larger pipe to handle the EDR I am running through it, so where ever is best, is where it/they will go.



Thank you,



Mike