iOS 7 Sprite Kit change zPosition in SKAction - ios

Question

I have two different SKSpriteNodes. The first is stationary and the second, I would like, to move around the first node. I have my second node is flying in from off screen with a zPosition of 11 (the first node has a zPosition of 10). When the second node flies to the opposite end of the screen, I have the node flip and fly back across. At this time I would like to change the zPosition to 9.
witch.position = CGPointMake(self.size.width + 200, self.size.height / 2 + 50);
witch.zPosition = 11;
[self addChild:witch];
SKAction *moveLeft = [SKAction moveToX:-200 duration:8];
SKAction *moveRight = [SKAction moveToX:self.size.width + 200 duration:8];
SKAction *moveDown = [SKAction moveToY:secondNode.position.y - 50 duration:0.3];
SKAction *moveUp = [SKAction moveToY:secondNode.position.y + 50 duration:0.3];
SKAction *flipRight = [SKAction scaleXTo:-1 duration:0];
SKAction *flipLeft = [SKAction scaleXTo:1 duration:0];
[secondNode runAction:
[SKAction repeatActionForever:
[SKAction sequence:
#[moveLeft, moveDown, flipRight, CHANGEZPOSITIONHERE, moveRight, moveUp, flipLeft, CHANGEZPOSITIONHERE]]]];
How would I go about changing the zPosition in the middle of an SKAction?
Thank you in advance for all suggestions and help.

Answer 1

This answer was found due to LearnCocos2D comment.
Adding a runBlock:action I was able to change the zPosition. The final code is:
[secondNode runAction:
[SKAction repeatActionForever:
[SKAction sequence:
#[moveLeft, moveDown, flipRight,
[SKAction runBlock:(dispatch_block_t)^(){
secondNode.zPosition = 9;
}], moveRight, moveUp, flipLeft,
[SKAction runBlock:(dispatch_block_t)^(){
secondNode.zPosition = 11;
}]]]]];