Chris I was trying to do some reasearch today on the inline engines. The only difference I could find between the 226/254 is the 226 has 4.4 stroke 3.3 bore. The 254 has 4.4 stroke 3.5 bore. Seems as though pistons for the 254 are hard to come by. Still don't know if the 226 can be punched out to 254.
Hey Chris, I aquired a 53 254 but discovered it had thrown a rod and punched a hole in #1 cylinder. I'm trying to decide if it can be, or is worth repairing, doe you know of anyone who sells a sleeve, rod and piston for them.