Aftermarket heads on my 289

Crs

Member
May 7, 2004
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San Francisco, CA
I'm rebuilding my original 289 on my 68. My question is it worth the cost buying aftermarket heads since my originals will need hardened seats, and other parts as well and still wont breath as good as aftermarket? I would like to get 280 to 300hp and have a fun driving reliable ride with an rv type cam, 9.0 -9.5 to 1 comp, 4 barrel intake and carb. Oh, and also a C4 with 3.50 gears. Thanks Guys!
 
I'm rebuilding my original 289 on my 68. My question is it worth the cost buying aftermarket heads since my originals will need hardened seats, and other parts as well and still wont breath as good as aftermarket?

Aside from the cost of rebuilding the originals, you'll need to factor in the portwork necessary for 280+rwhp. The aftermarkets will start looking better after it all adds up.
 
Unless he's going to drive it everyday, he really doesn't need hardened seats. Just a good valve job and open the exhaust sides up will get him what he wants. If he does shop for heads, he needs to stick with 58 cc chambered heads only.
 
I suggest you get a valve job done and port them yourself....its not that difficult to clean up the chambers and open up the ports a little with a grinder and a little patience. Do a search for DIY porting and you'll get some info.

It wont be a professional port job, but:

1. it will def help
2. it will cost next to 0
3. its fun to learn
4. you can tell your friends "nah, I ported em myself, man." :)

Otherwise, for olt-on, out of the box I would suggest Edelbrocks.
 
I suggest you get a valve job done and port them yourself....its not that difficult to clean up the chambers and open up the ports a little with a grinder and a little patience. Do a search for DIY porting and you'll get some info.

It wont be a professional port job, but:

1. it will def help
2. it will cost next to 0
3. its fun to learn
4. you can tell your friends "nah, I ported em myself, man." :)
:nice: :nice:
 
I have a mild 289 (1968) as well and was wondering of these heads would drastically reduce compression and hurt performance. Just got a classic over summer and this is my first question on stangnet. Any help would be much appreciated thanks guys
 
I have a mild 289 (1968) as well and was wondering of these heads would drastically reduce compression and hurt performance. Just got a classic over summer and this is my first question on stangnet. Any help would be much appreciated thanks guys

there might be a slight compression loss due to the extra 4cc combustion chamber size, but the improved flow through the ports, and the improved combustion chamber design negate any performance loss that there might be from any compression loss. in fact you will get a decent performance increase. these heads are a 40hp bolt on.
 
You say the engine has 145k on it now? Sounds like it could be nearing the end of its life. Then again, if theres no knocking and no burning oil or leaks, it may be just fine. I would check the timing chain when you tear it apart. They can get pretty stretched with that kind of mileage and dont give any warning before slipping a tooth, or breaking altogether. As for cylinder heads, how about a set of gt-40s? They already have hardened seats and can be found for around $400 a set new. Im not sure if the spark plugs in the "P" heads will clear the exhaust setup that you have (Im assuming stock manifolds), but the 96 and possibly 97 heads have the standard old spark plug location. Bolt on a set of FRPP cobra roller rockers and youll have yourself a nice combo on the cheap that will easily support 350 hp in stock form.
 
Probly not on ebay, but you can at your local parts store. Tell them you need new heads for a 96 Explorer v8.

I realize this context is a bit of a highjack (damn A.D.D.), so I'll repost this on a new thread...

gt-40p heads.... spark plug angles for headers=:( At least as far as I have heard.

This gives me an opportunity, what about these Procomp deals floating around

http://cgi.ebay.com/ebaymotors/FORD...270084903825QQihZ017QQitemZ270084903825QQrdZ1

Not that I contend they match up with say, Edelbrock, AFR, RHS, or any of the other big names. Still, if you're looking at reworking stock heads, can these be, economically and functionally, a better alternative?

I mean, for 750$, after springs etc., how bad of a deal is it. Especially since a friend of mine had his heads redone, broke several guideplates, bought several sets of springs, took them back and needed more work, he is way over 750$ (the valve spring reliefs were not deep enough). He talks about these Procomps all the time. Usually while spitting.

See here:

http://www.mercurycougar.net/forums/showthread.php?t=21240

and here:

http://www.mercurycougar.net/forums/showthread.php?t=23744

and here:

http://www.mercurycougar.net/forums/showthread.php?t=25925

and finally (hopefully) here:

http://www.mercurycougar.net/forums/showthread.php?t=26994

All because the machine shop failed to do it right the first time.

I am not trying to scare anyone (although I'm frightened, myself), i just wonder if a trip to the machine shop on these old heads is even worth the trouble anymore.

Let's face it, not every machinist is a genius or even easy to work with. Getting an old set of heads reworked can be costly, emotionally and fiscally. Why not just bolt a set of these Procomp deals on for a budget build?