This is how i did it on both my DTT installs,it may not be 100% right,but it worked for me. While I was pullling the trans to do the upgrades,I laid the new TC down,. and started fillling it with fluid. I set it down at an angle with the TC drain plug facing uphill,I took out the drain plug,so it would act as a vent,then added about 1 1/2 quarts of ATF to the new TC,put the drain plug back in,and tighten it. After the transmission is upgraded,installed,and ready to run. ,I add about 7 quarts to the stock pan,. with a DD pan,you should be able to add 10-11 quarts easy. Then i set the parking brake,put the trans in N,and open about 5 more quarts of ATF,once the lids are off the fluid,and the funnel still in the Fill tube, I fire the motor,and immediately add the 5 quarts to the transmission as quick as i can get the funnel to take them. I check for leaks,then check the fluid level,top off as needed. This works for me,I like to get at least 80% of the fluid in there ASAP,I dont like the thought of the pump sucking air,running dry because i took my time adding ATF. Good luck.