I have a British (A&AEE) tests of:
Airacobra AH-573
7,830 pounds
Allison V-1710-E4
2600 rpm
37.2 inches of Hg.
2,000 feet - 2040 feet per minute
10,300 feet - 2040 feet per minute (critical altitude)
16,000 feet - 1385 feet per minute
22,000 feet - 795 feet per minute
29,000 feet - 120 feet per minute