Here ya go Mike! I just noticed this. Not all of the Mack engines had the same size pumps. I have numerous slides of the macks, and quite a few have the smaller 1000 gpm pumps. Can anymore verify this for sure?
Engine 22
1974 Mack 1000/500
John Schmidt Photo
Engine 30
1972 Mack 1250/500
Tom Bair Photo
Originally assigned to E29
Engine 32
1973 Mack 1250/500
Tom Bair Photo
Engine 51
1972 Mack 1000/500
Tom Bair Photo
Engine 22
1974 Mack 1000/500
John Schmidt Photo
Engine 30
1972 Mack 1250/500
Tom Bair Photo
Originally assigned to E29
Engine 32
1973 Mack 1250/500
Tom Bair Photo
Engine 51
1972 Mack 1000/500
Tom Bair Photo