*Note I altered the hand slightly for the problem if you look it up.
T1: ♣4 - J - Q - 3
T2: ♦9 - K - A - 3
T3: ?
Opponents have a switch auction and you lead the ♣4 which is your system lead from xxx. Partner wins the Q, declarer following with the 3.
Partner now returns the ♦9 to declarer's K and your A.
Now you've come to the crossroads. Do we need to cash another one of partner's clubs or do we try to give partner a diamond ruff? We play standard returns, so partner will return the ♦9 from 9 or 9x.
Here's what I thought was the interesting part of the problem. What do you envision partner's hand to be? Would it be consistent with the bidding and the play thus far?
What do you envision declarer's hand to be?
Advanced/Experts please feel free to show your answers as I think the thought process is the most useful part.

Help

P - (1♥) - P - (2♥)
P - (4NT) - P - (5♣)
Dbl - (5♥) - All Pass