Pondering 351 Heads For My 289

robbz28 · Jul 13, 2012

Hi all, I have a pretty much stock 289 c code in my 67 coupe. When I got the car the engine ran too good and did not smoke for me to mess with it, so I simply did a mild tear down and put in some new gaskets. Money was a HUGE issue at the time and just didn't have it to spend on the motor. It has been bored .30 over and the block and rotating assembly looked really good, bearings looked good, no score marks or anything. The heads needed some new valve seals and that was it (factory smog heads) I put a performer RPM knock off intake on the top of it and a 600 4bbl holley vacuum secondary. I also converted the points to electronic. I also am running full tube headers. The engine runs great, starts up easily and is at a minimum "peppy" but I want a little more "oomph" out of it and was thinking about the heads. What if I swapped them out for some DOOE 351 heads? I really don't want to have to change my camshaft...I don't have any specs on it, but I am assuming its a factory spec piece.
I am trying to put a band-aid on my new motor wants! I want to spend about 500 bucks and a weekend and quench my thirst for speed....for now.
It is currently hooked up to a c4 with the factory 2.79 gears. That will change this fall with a T5 and some 3.73 gears...so keep that in mind when making suggestions.
Thanks in advance!

MitchGT · Jul 13, 2012

why waste money cleaning up old heads, which still won't be very good, when you can buy some good heads that give you room to grow into them. If you buy these, you'll still probably end up buying better ones eventually anyways...

robbz28 · Jul 13, 2012

Eventually you are probably right, but that could be 2 or 3 years down the road, so let me rephrase my question. What kind of horsepower gains could one expect from swapping the factory 289 heads to 351 dooe heads with my current setup?

Noobz347 · Jul 13, 2012

robbz28 said:
Eventually you are probably right, but that could be 2 or 3 years down the road, so let me rephrase my question. What kind of horsepower gains could one expect from swapping the factory 289 heads to 351 dooe heads with my current setup?

I don't know how much HP you'll end up with for a set of 351 heads (guessing less than a 302 equipped with E7s) but I have to agree with the other guy. You can get good set of used aluminum heads for 5 to 6 hundred dollars, already built up and ready to go. I've seen 190cc heads and 210cc heads go for that amount.

"Down the road", as you say... You could port and polish those heads to go even further vs. tossing them out to replace them.

robbz28 · Jul 13, 2012

Well this is a little off topic...but i found a pair of 65 hipo 289 heads the guy wants 150 bucks for...i know they arent THAT much better than what i got...but i might can sswap them out for some good heads.

woodsnake · Jul 14, 2012

Do you know how to verify that they are in fact "Hi-Po" heads? Or are they just fresh?
In all honesty, I feel your pain. I have been working on my cougars for the last, oh....20 years or so. I bought an engine kit/cam kit for my 67 in 2005, and it is all still new, sitting in the box, in my kitchen. I am going to try and build that motor in the next couple of months, I just need the machine work, and pushrods. I have everything else...
At the end of the day, if you have a solid performing, reliable car right now, leave it alone! SAVE YOUR MONEY, and stay on the look out for deals. I don't know, (Or need/want to know) your situation, but patience pays off. Cash money still goes a lot farther than credit, especially when you are dealing with person to person stuff.
Craigslist is your friend for some of that stuff...

robbz28 · Jul 14, 2012

Yea i can verify...but the guy that has them dont even know what a valve spring is...so i have been tezting him questions. They are not fresh at all they will need reworking. But i might can flip them and buy some better heads later. They are 100 miles away and i just wanna know before i make the drive

woodsnake · Jul 14, 2012

I'll save you the drive, and say no....When a guy has ford parts, and wants to sell, everything for a small block is "BOSS 302" or "Hi-Po"...

65FBE2 · Jul 14, 2012

I used 351 heads in the past, they need the exhaust ports opened up due to the smog bump in them. If you do this then mill them .04 to regain some of the compression you will lose, they work great. You will see about 40 hp gain. I would recommend a solid lifter hipo spec cam. Comp makes a tight lash version that works great and isn't to noisy.
Just my .02 on your planned tranny and gear swap. If you buy a t5 wc tranny (3.31) First gear will be way to deep for the street unless you are racing it. I have a T5Z with a higher 2.95 first and 3.25 rear gear and for street use, it's perfect. 3.50 rear would be as low as I would go. If racing is your goal then 3.70-4.11 would be fine.

Couped Up · Jul 14, 2012

About the Hipo? heads...... Check-em out! Have him send you some pics, or ask him if there's two dots above the numbers 289....I doubt they're real, but if they are, you could probably make enough off the sale to buy a nice set of heads.....

Just my .02 sense....

bartl · Jul 14, 2012

The D0OE heads have 60.4cc chambers. That means you're going to lose about 3/4 point of compression. The "HiPo" heads don't give you any real advantage other than screw in studs and valve pockets. What I would do is take your "smog" heads and do a port and port match, removing the smog bumps, have the valve seats and guides replaced to use either 1.94/1.60 Chevy valves or 1.84/1.56 351W valves.

Edster · Jul 15, 2012

I built a 302 for my Falcon back in the early 90s, The car came with the D0OE heads That had been ported. If the car didn't have 'em I would gone aftermarket. If ya got a set run 'em if not try to find some good used aftermarket heads. I prefer iron because they don't warp if your engine overheats.

Rusty67 · Jul 16, 2012

Just for the record, the 69/70 351w heads are better then the E7TE heads and are actually what the GT40 heads were based on.

If you have a set of 351w heads around then have them mildly worked, bolt them on and go. I would do screw in studs with guide plates and a set of roller rockers while you are at it. If you use the larger rocker studs then you can take the rockers with you to your new heads.

Pondering 351 Heads For My 289

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