When I did my clutch on the Barracuda, I went with the diaphragm style too. Wayne at Brewer's told me that if the pedal didn't come all the way back up from the clutch fork spring itself, he commonly gets a throttle return spring, or something like it with a long pull and mounts it on the clutch pedal to somewhere under the dash to help pull it back up into home position.
On mine, the spring on the clutch fork is bringing it back up fine and I didn't have to add one under the dash. May have to over time, but for now it is working fine.
