1988 5.2 which intake port size?

A 318 is a 5.2L, just depends on the measurement unit used. i'll bet the factory emissions decal on the truck says its a 5.2L.

And in Mopar world, it's a 318 until the Magnum line came out in '92/'93, at which point it's a 5.2. A 5.2 and a 318 have the same displacement but are not necessarily the same engine line. 318 is LA, 5.2 is Magnum.

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