Gone in 60 seconds...

[thunderbolt]

the 69 and 70 Boss 429 was the first but the 71 mustang came optional with the 429. This was not the same hemi head 429 as the boss but a wedge head version. The non boss 429 lived only 1 year in the mustang, 1971. Horse power in 71 was gross and in 72 switched to net numbers used today. This translates into what appears to be a loss of hp but is really only a different way of calculating it. So 375 in 71 does not equal 375 today. I forget the numbers, but I think multiply by .7 gets you pretty close generally. A recent dyno test I saw put a rebuilt 429 just barely ahead of a 4.6 that was not the cobra motor. The 429 has a whole lot more bottom end grunt, but technology has been great for modern engines. Now, give me a 460, modern heads, roller valve train, good induction, liberal fuel injection and an ignition curve to match and just try to hold on, but that is some work.