RS Motorsport :: Classic Speed Restored

I am just getting all my bits in a line for my head to be rebuilt. Got new valves, some guides, the springs that came with my BCF2 cam kit. I realised I needed some new collets though as the new valves have 3 grooves instead of just 1.

But when I got all my bits out I noticed that the exhaust valves had a different spring cap on them. The thicker one on the left was on the exhaust springs.



This is a pic I took while pulling it apart



All the other spare heads I can see have caps that look the same, like the following.



These are the springs, the 2 on the left came off the old head, the one on the right is the new one. All the springs in the kit are the same length.



Is there any reason for the different ones on the head that I've pulled down? When putting it back together do I use the same caps that came off the head?

And one other question, I also noticed that one of my other spare heads has all these tapped holes in the end near the thermostat housing. Any idea what they are for and why all the other heads don't have them? (sorry about the crap photo)

Have you compared the valve lengths of the old an new valves?
I would use the parts that came in the cam kit together.
Head with holes in them near the thermostat housing is probably a FWD head (Fiesta).