Chosen Solution
Can a Dell Streak 7 (wifi) 4G be modified to accept a sim card and used as a phablet like the TMobile Streak 7?
No, even if you got the Sim card slot to work, T-Mobile blacklisted all the IMEI numbers for the Dell tablets. There is a version of Cyanogen/LineageOS that enables phone calls on models with a SIM slot, however it is blocked on T-Mobile’s side. You may get lucky and get another carrier to accept calls with the tablet.
