just learned something.. they are listed as 1/4 3/8 1/2 etc. but really aren`t,, i have been using a true 1/4 stoke increase in my engine analyzer program , will have to change that.. the spread sheet i posted originally came from this forum so i guess the author didn`t know that either..The problem with that is the stroke options are incorrect. Falicon is 78, 81, and 84.5mm, not 1/4, 3/8, and 1/2" as so commonly thought.
The 1250 bore and 4.25" bore are different cylinder sizes. They do not bore the cylinders they machine the engine case to accept the bigger cylinder sleeves. You will need to bore the case if you have an 1130 to install the 1250 or 4.25" sleeves.Thank you all for the links and info. I saw some pistons all different sizes for the v rod it seems like too many sizes for the combo's I have seen and read about. The 1250 liners how far can be bored out? (Safely) Are there aftermarket liners that require the case to be bored bigger or they just boring the 1250 liners out more?