help please,4 speed conversion qusetions

i want to convert my 67 cuda to 4 speed. I just found a guy with a complete setup ( except bellhopusing) for sale locally.
I dont want to waste my money so I have several questions, before i drop the dough.please>
the motor in my 67 cuda is a 1971 340 with a 904 behind it, i dont know what year the tranny is.
the 4 speed setup for sale was installed in a 1971 dart with a 273.
1) what about all the clutch linkage, was that the same between a 67 cuda and a 71 dart.??
2) what about the bolt up between this guys flywheel and the crank in my 340, i heard that there was a change between 67 and 68 in the small block cranks
and a 67 flywheel wont fit a 68 crank or vice versa. true???
he says that the flywheel is the larger 130 tooth flywheel
thanks a lot, i am so frustrated that there just doesnt seem to be any definitive info on mopar 4 speeds, i get conflicting stories everywhjere i go.
neal