Jerry's comment about modifying a 216 is what I did, although I didn't get as large as 250 CI.
There's some discussion about my project in
this thread and also in my Project Journal
starting witih this post.Along with the 235 crank and rods, I used 1950 Chrysler 250 pistons (0.080 OS), and installed a higher capacity oil pump and had the block machined for a full circle rear main seal. The pistons only worked because my engine was standard bore, so if a 216 is already bored out, those wouldn't work.
