They do require adjustable rocker arms, stock length pushrods are fine. I have them in my 87 W-150, its lifted 4 inches 33 x 12 Dick Cepek's. Out on the highway i average 24 mpg, with a mildly cammed 318. I can roast the tires on a whim, its a super torquey motor for it size. I have mine set to .025 for normal use. The ticking noise is barely audible.
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