[Dave at Pelican Parts]

Conventional wisdom is that cast-iron cylinders larger than 96mm tend to have cooling problems and are not that dimensionally stable, leading to compression leaks down the road. Most people feel that when you go larger than 96mm, you need to find biral cylinders (e.g., try to locate old Oettinger 100mm ones) or go with the Nickasil ones for big big bucks.

I have no real data about this myself, however.

--DD