did you replace all of these?
If so then do a compression test.
It may also be a sticking valve.
As for the noise at the back it could also be a few things. Is the car feeling too tail happy? If so my guess is subframe bushes.
If its clinking at hard accelaration then its either drive shaft or diff related.
"Lo there do I see my father.
Lo there do I see my mother.
Lo there do I see my brothers and my sisters.
Lo there do I see the line of my people back to the beginning.
Lo they do call to me
they bid me take my place among them in the Halls of Valhalla,
where the brave may live forever"