Glad I found this thread. I was scrolling down looking for a clutch pedal to convert a '69 cab to manual. The cab will be going on an '89 C30 with hydro boost brakes and external slave. I was already imagineering a way to get this mismatch to work. Seems you've already done that..
The '89 already has a new clutch master on it. Any way that would work with your kit ?
Thanks