To De-Smog or not to De-Smog...

63valiant said

I have to disagree, smog equipment and specs are notorious power and fuel economy robbers. The slant is just one example of the before and after of the smog regulation. The early 60's slants were quite strong stock, the late 70's slants barely got out of their own way.

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There is a bit more to the apparent loss in power than than just added emission controls. In the 60's, gross power was measured at the flywheel while, in the 1970's, net power was measured at the rear wheels. Also, larger tires (14" from 13") and lower ratio axles (like 2.76:1 from 2.93:1) were used to improve fuel economy, which had a detrimental effect on acceleration.

There are ways to improve fuel economy and power without removing the emission controls. You would probably notice a bigger improvement in both with a rework of the advance curve than by yanking off the smog equipment. I've also used the EGR in my 73 Dart to run higher amounts of advance for better fuel economy as carbon was causing knock with 87 octane.