We are wrapping up the 5 spd swap to my 78. After my friend installed the pedals we saw that the pedal is really close to the firewall. Is this normal b/c it seems that the master cylinder is short even being adjusted out all the way

Here's a diagram for a 75-78. See attached.

Just make sure that when you're all done adjusting that you still have 1/8" to 3/16" free play in the pedal before it starts to depress the master cylinder. Otherwise you'll have problems.