I like the engine to assist in slowing down. Can you explain how the DFCO table can assist in this matter? I have an LT1
My LT1 table is 400-1200 rpm its .8% tps, and 1600 is 1.2% and 2000-3600 rpm its 1.6%, if this makes sense?

 

What they have there are the max TPS values (I think) for when DFCO can become active. Cutting the fuel does help engine braking, and as a matter of fact, even without DFCO, the fuel will automatically cut out due to the extremely short PWs during decel.

If you want more engine braking, looking into adjusting the min throttle follower IAC airflow is what you really need to do. If you close the IAC all the way during moderate/high RPM decel, you will pull max vacuum. It comes at teh price of stressing the rod bolts a bit, but you get the most engine braking possible.

 

With an auto trans, you'll also have to consider the sprag clutch in 4th range allowing the driveshaft to overrun the input drum.

 

Reduce your timing in the overrun areas (low MAP cells you never use except coasting).
Will put your head through the windshield when lifting if the trans is pushing the motor.