LEM-
>>On a wet rwy acc stop dist do account for reverse thrust for stopping, and a screen height of 15 ft instead of 35.
The above on a twin. Any differences on a 4 holer?<<
That's a recent change to the certification rules. (About 5-6? years ago.) All ac certified earlier than that, and those under SR422a and SR422b, like the DC-8, DC-9, 727 etc, can't take credit for reverse.
In the context of the original question, mutt is correct.