Thread: 289 c6ae heads Vs 1990 5.0 stock heads

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I have a set of 289 heads casting number C6AE and I was wondering if there would be any benefit to using these heads instead of my stock 1990 Mustang 5.0 heads. If I had a choice between rebuilding and using either set which would yield the most power? Response? Torque? I'm just wondering because these heads were given to me and if they aren't worth using I want to get rid of them. Thanks in advance,
-Erik

actually those 5.0 heads will give you higher compression, so increased power decreased fuel efficiency... but thats life... i'd stick with the 5.0 heads unless you live in california, then go with the 289s cause gas mileage is desperate here... i'm considering putting a 5.0 intake on my shelby 289 just so i get the gas mileage from the fuel injection...

hey Eric,

What do you plan to do with the motor? If its just street driving rebuild the best set. If you want to make some power go aftermarket. No stock cast windsor head is very good. You will spend as much on porting them as an aftermarket set will cost. Go to Air flow research site and go to the articles there is a great head article there and they include the E7's and everything else.There are a lot of great windsor heads out there.
Good luck

I guess that I'll just go for a set of aluminum heads. But considering the price of an intake (which I'd like to switch as well) along with the heads and maybe a stronger cam, I'd be almost as well off to save the money and buy a GT-40 long block from Summit and just get a good intake. Along that line, does anyone know what the "Ford Motorsport Adapter Kit" is that Summit claims is needed to use the GT-40 with any 79-93 mustang???


Thanks again,
Erik

Um, if I'm not mistaken, those '66 heads have smaller chambers, and will produce better compression than the later 5.0 heads. The later heads are often referred to as "smogger Heads" Low comp. emissions heads. Bad news for power.

I have to concur with ricebasher. I run '66 289 heads on a 306 (.30 over 302) and it's got serious balls.

I don't know the exact specs on the heads and I'd be eager to know; I've been told that it's a free-breathing, high-compression head. What I DO know is that the response is killer and the torque shakes the whole car. I'm sure it won't stand up to a set of Trickflows, but I'm told it's as good as you'll get with cast-iron.

My suggestion is to try them both; swapping heads on a 302 is only an afternoon's work, and just costs you a set of gaskets.

And if you find that the 5.0 heads are more to your liking, PM me and I'll take those 289's off your hands. Seriously.

Don't let some of the guys pull your chain.
I've been into fords for the last twenty years.
C6AE head is Identical in comparison to the HP head of 66,
chambers are the same valves are the same.
The 289 in 1966 -271 hp with a 4V carb.
the thing with alot of the newer heads is that they flow
more air. Now you can get a horse power jump if you use the older head to get more compression. And this is a easy way to get cheap hp with out tearing the whole engine apart.
But if you have money to burn the best way would be to install some pop up piston with some good after market heads/w guide plate and the whole shabam. This way you have the best of both worlds, higher compression and better flow.


~ Vegas ~

What are the chamber and valve sizes in the '66 HP 289 head?

In 1966 the @98 head had a chamber size from 52.0 to 55.0 this works out to be about 10 to 10 1/2 to one.
Valve sizes are exhast 1.45 and intake is 1.78
port sizes are intake port 1.04 x 1.94
exhast port size is .96 x 1.24
And uses conventional rockers.
Hope this helps,
sorry it took so long to answer but I just got back from work.


~ Vegas ~

I'm not really too familiar with any of the post '80 302's but aren't the rocker assemblies 'bolt down' style rockers? Personally I really like the older stud mount rockers better. And i do believe the studs on that head are 3/8" studs unlike the post '73 302 heads which are 5/16" with a torque down style rocker nut.
My heads CC's out to be 54.5 (I have '66 4V castings) and had them ported out and added 1.94/1.60 valves. All costed about $550, but this was in 1996 and very few aftermarket heads were really affordable then.

The BEST route would be to just go with aftermarket heads if you want to get really serious. When on a tight budget the '66 castings, with a few mods, would be just fine. Though I'd still research aftermarket units as prices have been declining.

Your typical cast piston nowadays will sit about .023 (give or take .005) below the deck (of a 289 or 302 up to '73) and depending on the valve reliefs (usually -8cc on a 4 relief piston) Will put you right around 8.5 to 9.3:1 on the compression scale with the 54cc heads and that includes a head gasket thickness of about .030 when compressed.
Where Ford comes up with 10.5:1 must be a pop-up piston or a different wrist pit height to make the piston sit higher in the bore. (common on FE engines)

I'd stick with the E7TE's grind out the egr humps and they flow pretty good. and you won't have to buy special headers.

No way. Small block ford heads have had no significant changes since their conception. Any header will fit on any sbf head. (besides GT-40s) 289s = better comp. ratio and less time spent grinding emission bumps.

Neither of those heads flows for crap.

If you just want a decent head for little $$$. Go with a gt-40 you can get them off the v8 explores and mountaineers with a little home porting (remove the emissions bumps) these heads flow pretty well. The intake off the explores also flows real close to the gt40s


These heads will be gt40 P heads which will require a different set of headers.

those gt40 heads are still smogger heads... best way to do it is cruise ebay for a deal like i did and pickup a set of 302 H.O. heads with roller rockers and guide plates already installed for $300, then get them ported and polished and you got it.. or if you can fun some tunnel port heads... those really flow good... but they had problems with the pushrod enclosures breaking, and then oil going straight into your vavles

Originally posted by thesals
those gt40 heads are still smogger heads... best way to do it is cruise ebay for a deal like i did and pickup a set of 302 H.O. heads with roller rockers and guide plates already installed for $300, then get them ported and polished and you got it.. or if you can fun some tunnel port heads... those really flow good... but they had problems with the pushrod enclosures breaking, and then oil going straight into your vavles

Smogger heads???? What are smogger heads? GT40s are the heads that came on the 93 cobras and flow much better than the E7s

302 HO heads??? If you are talking about the stock heads off the 87-93 GTs Those are E7s and flow like crap.