I changed the disc and throwout bearing on my '87 Firebird. Now the clutch does not engage until the pedal is almost completely released, meaning the clutch slips until the pedal is at the very top of it's travel. The new parts were the same spec as the old. Before, the clutch bite and release point were closer to the floorboard and much more comfortable to drive.

The pedal also feels stiffer when depressed until the very bottom when it suddenly gives way.

The hydraulics on the slave were not disconnected during the install, however the retaining straps on the slave cylinder were broken, I'm not sure it this has any effect.

The pedal does not appear to have any means of adjustment. What can I do to fix this?

 

The straps on the slave cylinders are designed to break the first time the clutch pedal is depressed, and should be discarded. The beauty of a hydraulic clutch system is that there is no adjustment to be made with the hydraulic portion. Assuming all parts matched what was removed, then something else is mechanically wrong. The two most common errors are attaching the master cylinder pushrod to the wrong stud on the pedal (some pedals have more than one stud) and incorrect bearing installation. There are numerous pictures here and elsewhere depicting both. A third (surprisingly) possibility is incorrect fork installation (wrong fork or wrong placement on the pivot ball.)

 

Make sure your TOB and fork are in the proper position like the photo.