Sorry it took so long for me to reply....thought this thread was pretty much finished.
There are many differences between the ls1 and lt1 t56 transmissions.
Major differences are that the Lt1 style uses a pull type pressure plate....as compared to the LS1 push type.
Another difference is that the slave cylinders are completely different..... The lt1 uses an external slave cylinder that mounts onto the bellhousing that pulls the pressure plate to disengage the clutch. The LS1 uses a internal slave cylinder that mounts on the input shaft of the transmission and pushes the pressure plate to disengage the clutch.
You asked " how do I know that the slave cylinder was engaging the clutch enough"........ I personally go by feel......I have driven alot of muscle cars and regular cars and it is pretty obvious if your clutch isnt disengaging enough..... you can feel it!!
The way I did my clutch pedal stop was by the following...
1.I installed the clutch master cylinder to the firewall. Obviously since I used a Truck master cylinder the rod was way too long for my corvette.
2.I made sure my pedal was all the way up and I marked exactly how much I needed to cut off the rod to make it mount to my pedal. Cut the rod n welded it back together.
3. I took a measuring tape and measure my 15/16" of travel and looked at the best loaction for the pedal stop.
4. Drilled and added a pedal stop. Here is a pic of the pedal stop to give you an idea of where I mounted it.
And here is a pic of my custom made center console plate to accomodate for the different location of the shifter. .
I also had to customize my crossmember. I lowered it 1" so the trans will not hit the tunnel of the car and moved it forward 1 1/2".
Since I moved my crossmember forward I had to lengthen the E brake cable to complete the swap. An alternative option to this is to weld a custom mounting plate to the crossmember. That would have been alot easier, regret not doing it that way, but it worked out well for me.
If you are doing this swap be prepared for alot of customizing and alot of work. I can take pictures of anything you might have questions about.