Hi roro,
Firstly, the carburettor being a vacuum secondary is designed to run as the factory intended, with the vacuum diaphragm positioned on the back L/H side (you facing the engine).
Vacuum secondary carburetors have vacuum passages built into the body of the carburettor to provide vacuum to the secondary diaphragm, which operates the secondaries when there is enough airflow going through the front primaries.
Regarding the pedal assembly, I used an XC Falcon throttle pedal assembly (which was manipulated a little) with some spacers coming off the firewall. This has brought the cable out just over a 1/3rd of the length along the firewall.
I then had a custom length cable made to suit my CVR throttle bracket, which is more or less the same as the Holley one which you have just purchased.
I chose to have the cable run (or pull from the back) as I wanted to alleviate the cable running from the front (giving the engine bay a cleaner look). The cable does weave and twist a little (however, touch 'wood'), it hasn't broken or jammed in the time of which I've now had it set-up (2 years +).
Hope this helps...
Cheers,
Trans-Am:cool: