Does the AHU have lower valve spring seats?

Trying to come up with everything I need to do a stage 2 or 3 cam with dual springs in my AHU.

I had the valves out a while back to clean up the horrid mess on the backside of the intakes, and never noticed a lower spring seat. Do they just stay behind in the head? I definitely didn't take them out at any point, but I don't remember seeing them.

It seems that dual springs would require them.

It's not so much the dual springs require them, the spring seats simply keep any spring from wearing into the aluminum head over time. Every virgin head I've pulled apart to memory has them, they're usually covered in oil and stuck in the bottom of the spring pockets. If someone was missing them, they are a very easily sourced engine rebuilding component for literally cents each.

I must have had them! I just cant believe one never fell out when I was scrubbing the nasty crap out of the ports for hours on end with the valves out!

Just trying to minimize downtime when I have the car apart and make sure I have what I need. Is there any concern about adding seats and binding the coils with a stage 3 cam? I assume no.

Update, My car definitely does not have these. I pulled the head and stripped it down to port it and install dual springs and the stage 3 cam. I have an alh parts head, but I doubt that has these.

There is barely any wear on the aluminum base of the head where the springs had been sitting.

Where might I find these things? A part number would be very helpful.

update again: a friend of mine had a couple junk ABA heads. One of them had dual springs and the lower perches I need. I'll be using those. It seems like obd 1 ABA engines have dual springs and obd ii have singles and no lower perch.