All 389 heads are D-port, just like 99.99999% of all Pontiac engines.
Round port heads only came on rare ‘68 through ‘74 Ram Air, High Output and Super Duty engines, in 400 and 455 cubic inch displacements.
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1964 Tempest Coupe LS3/4L70E/3.42
1964 Le Mans Convertible 421 HO/TH350/2.56
2002 WS6 Convertible LS1/4L60E/3.23
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