I'm not sure it was. I have a 71 Mach 1 with comp suspension that was originally manual steering (and drum brakes) and when I swapped in power steering, I found no difference in the supposed manual idler arm. Now, I did find a complete PS system off a 71 Mach 1 which bolted right in. I did need to find correct pulleys though and I got really lucky there by finding a set on the net that were even date code correct! As for the idler arm, I did replace that later with the best part available from NPD. I've run this now for about 10 years with zero problems.......... except needing to rebuild it all due to wear.