Long stroke or long rod?
Were the power valves functional?
What kind of cylinders were they?
I believe the power valves smooth out the hit but you end up with about the same top end, just not like a light switch your used to ...i think
Some will confuse that with lack of power, when in fact its the same , your just not going from very little power into a light switch powerband.
Making port timing the same but matching the new "stroke" ( which nobody would do but) stroking will give you a little more torque
Stroking the athena will not kill top end but you'll have to get any/it ported to match the stroke change.
You shoulda went cpi or drive line tho, now you've gotta decide whats the better choice... to go with, to continue.