[James Renfroe]

If memory serves me well, the 2.0 and 2.2 are based on the 66mm stoke cranshaft. The 2.4 and 2.7 use a 74mm stoke. Many folks like to use the 2.2S pistons in their 2.4 (with the appropriate cam, they are interchangable given their 84mm bores). Cylinders are interchangable between 2.0, 2.2, and 24 given their case spigots are the standard 92mm (if the appropriate cranks are used. The 2.7 has 97mm spigots. All this is in the 911 bible (Wayes 911 book).