i want to say 6 bolt as well, so you won't be the only one with egg on ones face.
and the only thing mentioned about the cranks was one could install a hemi crank in a wedge block, but then had to use hemi length rods.
Two things on the stock stroke RB and 426 Hemi cranks, they both have 3.750 stroke and both type of rods from either motor will bolt on and work on either crank with the correct pistons and wrist pin location
As far as the 8 bolt cranks all V8 cranks in Mopars made before 1962 had 8 bolt cranks with studs in the flex plates or flywheels and a longer crank flange sticking out further behind the block (for attaching the retaining nuts on them) than after 1962.
When Mopar brought out the 426 Race Hemi in 1964 they went to the threaded 8 bolt cranks, not in the stock Max Wedge motors ever
That being said I've heard the rumor about MAYBE(made up rumor
) some of the hemi cranks got put into some of the last M.W. motors made in Feb. And March of 1964, NOT SO
I can't remember ever seeing a standard radius crank in a production motor after 1962, all the race cranks (Moldex and the others) Mopar, Direct Connection and the others they sold back then had the full radius cranks making using a stock rod bearing a pain on chamfering the edges
For those of you who don't know Mopar used a reverse radius crank for all production motors, slant 6 and V8 I've seen made after 1962
I'm not sure about the cranks used in later 4 cylinders and V6 motors
