[curtis73]

There are two main reasons why they don't stroke 305s with stock cranks. 1) the bores on 305s are pathetically small and stroking them would make poor breathing and a very poor bore/stroke ratio. 2) the mains on 305s are smaller than other small blocks, so the cranks won't physically fit.

For a while there were companies making the small-journal stroker cranks for 305s, but they lasted about as long as the popularity of the 305. The aftermarket only supports what we capitalist gluttons are willing to buy and the 383 is just a hot ticket.

The 307 is a little better in the bore department but still pretty small, and why stroke an oddball 307 to 350 cubes when you can pick up a 350 with a better bore for $50? Just not practical. I'm sure its been done, but not commonly