[67Lemons]

Looking at the Speedmaster heads for Pontiac on their site they clearly look like D port heads now where I always thought that they were round ports?

https://www.speedmaster79.com/Pontia...-Cylinder-Head

[misterp266]

Not sure how you see d ports but no, they don’t make them.

[charlie66]

there not D ports. There round ports

[performerrpm]

they are D port in shape but in round port configuration. they are not the standard d port like a 6x head tho...same as an edelbrock d round port head....i have both sitting on the shelf. not a bad looking head imo

[67Lemons]

Originally Posted by performerrpm

they are D port in shape but in round port configuration. they are not the standard d port like a 6x head tho...same as an edelbrock d round port head....i have both sitting on the shelf. not a bad looking head imo

Ok, thank you, I thought looked more like a D port than a round port, glad my eyes aren’t playing tricks on me. They look like a nice head but since the only available option for round ports is headers on my ‘67 I’m not the guy for these but they seem like a nice option for those looking!

[performerrpm]

there use to be manifolds avail...i dunno know about now tho

[67Lemons]

Great explanation here from the Butler site

https://butlerperformance.com/n-1308...ound-port.html

[performerrpm]

i have some edelbrock D ports just incase your looking

[67Lemons]

Originally Posted by performerrpm

there use to be manifolds avail...i dunno know about now tho

It looks like RARE & others stopped making the round port versions for 64-67 cars but have them for 1968 & up.

[b-man]

D-port and round port heads are quite different.

The difference is easy to see, especially from the exhaust port flange which is where the description comes from:

http://forums.maxperformanceinc.com/...d.php?t=636309

Just because the exhaust port floor is flat on aftermarket round port heads doesn’t mean they’re a D-port head.

Pontiac D-port heads almost should be called oval-ports because the exhaust port shape is oval, the two center ports squeezed in back to back are the only D-shaped exhaust ports.

That link to the Butler website only half explains the difference between the two exhaust port types. Either one could be D-port from that picture they show and it just raises questions rather than give any clear answers.

For the uninitiated among us they should have included a picture of at least a factory round-port head that actually does have perfectly round exhaust ports. Also a factory D-port is a lot more D-shaped than an aftermarket aluminum D-port exhaust.

If you’re using headers running round-port heads is head and shoulders above D-ports. Getting the bolts in and having access with a wrench on round-ports is so much better that once you’ve had round-ports you won’t ever want D-ports.

[Domarinolo]

Originally Posted by performerrpm

i have some edelbrock D ports just incase your looking

Do you still have the heads for sale? D port? What cc? Thanks in advance

[performerrpm]

Originally Posted by Domarinolo

Do you still have the heads for sale? D port? What cc? Thanks in advance

no sir,i gave up selling those and made piece with keeping them. there is a good deal on 1 head in the sell section that you could buy a single from summit and still be in pretty cheap for a set