Let me start out by saying that the potential park brake clearance issue has been resolved by Ross at Malwood. He was quite helpful.
I have two 1968 Barracuda pedal frame assemblies. One for an automatic, one from a 4 speed car. Only difference is the 4 speed car had a brace across the front. Mine was broken and I had a professional welder friend repair mine.
Other difference I found was the pivot shaft for the brake pedal was longer on the 4 speed. More later on how that could matter. The groove on right is what locates it in the frame. So the bottom one would stick out more on the side the clutch pedal assembly attaches to.
Here is a factory four speed pedal assembly:
Here is the older version of the Malwood kit installed on my car. Pedals came out very close together. I did a facetime phone call with Ross at Malwood and we could not figure out how or why mine was different.
Here it is on the bench:
And a youtube video showing the park brake clearance issue. The clevis rubs on the corner of the assembly and the lever sometimes catches on the bolt head for the clutch pedal pivot. If you were to install this with the longer style pivot shaft it would not clear at all.
Ross made a change to the pedal location and sent me the new version of the kit. He had already made a design change to help with the park brake lever clearance issue. He moved the assembly up closer to the firewall and that allowed it to be closer to the pedal frame.
Here is the old version in the left vs the new version on the right:
Here is the new version installed in the pedal frame on the bench:
Pedals are 5-1/2” center to center and with the stainless trim there is about 1-5/8” space:
Here is the new version installed in the car:
Here is a video showing the park brake clearance:
If you are forced to use the longer pivot shaft the built in spacer on the Malwood assembly might have to be shortened 1/4” for everything to line up perfectly. But, there is enough space now it may not be an issue.