WELCOME TO AR
Test E would be best to run for at least 10-12 weeks as the long Enanthate ester can take up to 6-8 weeks just to fully kick in so you would be ending right at its peak, 250mgs/week is a rather low dose just so you know. Also, I would not run the dbol longer than 4 weeks.
You may want an AI like arimidex or letro during the cycle to help with the water retention