'65-'70 Chevy fullsize cars have the gas pedal mounted on the floor just like the Z28s.
Chad

And this is how I find good used ones. The part number is the same.

To confirm, this is a 1970 and 1971 Z28 thing.

Mike

Yes, 70 and 71 only

If it was a racing heel toe thing it had to come from somewhere. Did any of the Penske cars in 69 change the pedal to floor mount

No the Penske cars did not. Very doubtful it had anything to do with heel and toe driving technique.

Chevy trucks from this era also had a floor mounted gas pedal.

Still a bit of a mystery. There had to be an internal memo or Engineering Change document somewhere in the bowels of GM noting this change. There were obvious costs and quality risks (see 70 COPO post #10) associated with this. Maybe it was a requirement from Vince Piggins or some other GM exec? As the power of the famed LT-1 dropped after 70 and "de-contenting" occurred to reduce costs it became less interesting for these niche changes to continue?

When checking 71 and 72 Z's and LT1 Corvettes make sure they have the original valve covers which are designed for the PUSH in Oil Fill cap... they are different than the others with TWIST in OIL FILL CAP.
Theses valve covers are near impossible to find...