Well, here is how I do a butt and or butts in the SRG.
I preheat the SRG on HIGH setting with pellets around the Tommy Ring for 15 mins to get the smoke rolling.
Then I trim the fat cap down a little then score it like a ham the rub with mustard then my rub (low sugar rub) then I place it in basket after I spray the basket with Pam cooking spray. Set your half racks to the middle if your only doing one butt.. Place the basket into the chamber (setting still on HIGH) let it run for about 15 more mins to start a good bark then turn to low and let it ride the INFRARED highway
Depends on the size of the butt, but they will go 4 to 6 hrs with a average 30 to 45 min stall. Start looking at
IT around the 3 hr mark and pull at 205 (trust me it's better at 205 then 200)
FTC for an hr or so then your ready to eat
Call me if you have questions, you have my digits