I thought heeltoe carried it but I only see the master cylinder without the delay valve. Sometimes my clutch pedal sinks before it engages. I think my slave cylinder may be going out and I want to replace with new.

 

I don't think so...they all have the checkvalve.
There aren't a lot of moving parts to a slave though...
you have intermittent pedal sinking? Or every time?
Have you adjusted the clutch pedal at all?

 

Intermittent. Happens rarely, usually after long highway drives.

 

I haven't tried adjusting it.

 

I didn't even think it could be adjusted. Thought it was self adjusting

 

it is a self adjusting clutch but there is pedal throw and initial resting position adjustability.
Not sure it'll help but you could start there. Inconsistent pedal feel probably isn't going to be
fixed by that though.

 

The one car I had with that symptom (intermittent low clutch pedal after long time not using it) was a master, not slave, cylinder issue. Do you know the master to be good?

 

I don't. I might do both. I want to do the delay valve delete too.