# Pontiac D-Port #66 Heads



## jtwoods4 (Dec 22, 2011)

I am trying to figure out which Header gaskets I need for my #66 pontiac D port heads. The options are:

Large D-Port
1-1/8" x 1-15/16" D-Shaped Center & 1-1/2" x 1-15/16" Oval End Ports
PONTIAC Header Exhaust/Manifold Gasket

or

D-shaped center ports, 1-3/8" x 1-13/16" oval end ports 
PONTIAC Header Exhaust/Manifold Gasket

Anyone know? The casting number for my heads is 481766


----------



## Eric Animal (Oct 28, 2007)

Those heads SHOULD originally be from a '71 455....325 HP. Hope this helps.


----------



## jtwoods4 (Dec 22, 2011)

So which 1 of those gaskets above will fit correctly?


----------



## Roger that (Feb 6, 2010)

Im confused, Is your cast number 66 or 481766? I found a part number 481760 which is for a head different from the 66 cast number head. If the heads are in your possession, just measure the D and Round port sizes to match them up with the gasket.


----------



## Roger that (Feb 6, 2010)

For your info, I know on my 65 GTO and other years throughout the 60s that Pontaic did not put exhaust gaskets on. They machined everything flat and just bolted in on.


----------



## rickm (Feb 8, 2012)

all pontiac d port heads use the same header gaskets from 65-74 except ram air IV.


----------



## jtwoods4 (Dec 22, 2011)

Turns out this is the gasket that fits hooker header
PONTIAC Header Exhaust/Manifold Gasket


----------



## geeteeohguy (Feb 2, 2008)

I hope you're running those heads on a 455 or 428.....they have big chambers, _really_ big, and will net you super low compression on a 400 engine....


----------



## jtwoods4 (Dec 22, 2011)

I am running them on a 472 stroker. (455 stroked)


----------



## geeteeohguy (Feb 2, 2008)

Great choice, then. Big valve heads that will work with today's poor fuel.


----------

