Smell of a Slam

Mersin Patton Team Matches.

♠ A Q J 8 7 5 2 ♥ A J 7 ♦ Q 10 3 ♣ —

West	North	East	South
			1 ♣
Pass	1 ♠	Pass	1 NT
Pass	2 ♦	Pass	2 ♠
Pass	4 ♣	Pass	4 ♠
Pass	?

What to bid over 4 ♠ ?

Our opponents pass to 4 ♠ as our team mates. Here is the full deal.

Board 1 South Deals None Vul	♠ A Q J 8 7 5 2 ♥ A J 7 ♦ Q 10 3 ♣ —
♠ K 9 6 ♥ K 3 ♦ J 9 5 ♣ A 9 8 4 3	N W E S	♠ — ♥ 9 8 6 5 2 ♦ 8 7 6 2 ♣ K 10 7 5
	♠ 10 4 3 ♥ Q 10 4 ♦ A K 4 ♣ Q J 6 2

I think North should make one more attemp over 4♠, maybe 5♣ is a good idea 5♦, 5♥, 6♦ and 6♠.