302 vs. 289 heads

Reply Subscribe

Thread Tools

Search this Thread

Nov 8, 2010 | 06:55 PM

#16

Greyf100

Elder User

Joined: Apr 2009

Posts: 725

Likes: 2

interesting...ty.

Nov 8, 2010 | 10:11 PM

#17

pcmenten

Posting Guru

Joined: Mar 2002

Posts: 2,070

Likes: 2

From: Boise, Idaho

So I'm wondering what, if any, difference there is between the C6OE head and the C5AE head. I have a burette so I can 'cc' the head if anybody is curious.

My head does have a thermactor bump, so that might explain why there's a new casting number/part.

Nov 9, 2010 | 12:17 AM

#18

BlueOvalRage

Cargo Master

Joined: Jun 2001

Posts: 2,571

Likes: 22

From: Oxford, Indiana

I think the Thermactor bump being added on the C6OE is it. I've got a set of each around here and that is the only difference that I see.

Nov 9, 2010 | 06:06 PM

#19

Beanscoot

Cargo Master

Joined: May 2007

Posts: 2,071

Likes: 36

From: British Columbia

Pushrod slots were used up to 1967 for Hi Performance 289 heads (which you are unlikely to come across).

Nov 9, 2010 | 09:03 PM

#20

xlt4wd90

Lead Driver

Joined: Sep 2003

Posts: 7,019

Likes: 210

From: SoCal

Aside from when the pushrod slots wearing out with age and you not being able to replace them, are there other disadvantages to them? Do the slots serve adequately as guides for the pushrods, even for high performance applications?

Nov 10, 2010 | 04:52 AM

#21

Old Hickory

Laughing Gas

Joined: Feb 2010

Posts: 781

Likes: 8

From: Sanford, NC

All 289 HiPos used the slot guides for alignment of the pushrods and had screw in studs
but no guide plates and they worked fine with a solid lifter cam. All of the early 289
302 heads had the same size small valves and ports which really restricted the engines.
Any serious power requirement needed much head modification. Back in the day both
Holman-Moody and Shelby American offered fully ported 289 heads with larger valves.
Today all these heads would also need to have hardened valve seats installed to
survive the unleaded gas.