One thing I don't know, again because I don't have any in my stash of stuff to compare, is whether the 235 and 261 cast flywheels are the same as the small block flywheels, just with the additional dowel pin holes. Having a small block steel flywheel drilled for the additional dowels might be an option if they are.
Probably apples and oranges, but my 168 tooth, GMC 302 flywheel is an alternatively drilled BB Chevy flywheel, made by McLeod. They still offer the BB flywheel and I would assume they could have the blank drilled as necessary.
