318, 340 and the 400...I do not believe the 440 was still available...
In 1973 the Available engines were as follows. Engines: 318 V8 170 bhp. (SAE Net) 340 V8 240 bhp. (SAE Net) 400 V8 255 bhp. (SAE Net) 440 V8 280 bhp. (SAE Net) 440+6 V8 330 bhp.(SAE Net)
there was no 440 6 bl. But there was an optional 440. U had to get get the GTX option on the road runner!
Simon is right. No six-packs were available after 71.
In 1973 best motor was 340 also available was 318 360 400 440+6 only in roadrunner/GTX440+6
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