In the recent discussion on Euro. vs US. the pollution control issue was mentioned. When I bought my '70-'71 car none of this system worked. A lot had been disconnected, besides which none of it exactly "enhanced " the under hood appearance. I removed it all - relays, trans. switches, and wiring, etc. - now - that did enhance engine appearance ! All of this system is separate from the rest of the car, so there is no interference with anything else. I upgraded the throttle body, and set the 1-2-3 distributor to match, and the engine response was much improved. I think drilling a new vacuum port in the throttle body would need to be extremely accurate, so I would recommend finding a correct unit. Whilst not being a"dramatic" improvement, it made the car a lot nicer to drive.