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I was reading about the advantages of using 351W heads on the 289 block. Something was mentioned about the early year 351 having larger valves. What year of 351W heads should I look for to get the maximum advantage from them and what needs to be done to them?

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As I understand it, the best heads are the 69-70 castings. After that, I think the valves were smaller. I'm thinking that in 75, they changed the shape of the combustion chamber, too, in order to satisfy more stringent emissions regs. Even the early heads could use some help on the exhaust side, though They have these large protrusions that were meant for air-injectors that should be ground away.

Glenn Morgan: 66 GT V-Burgundy Fastback 351w+toploader+9 in. TracLoc. Started out as a rusted-out Chicago-area crusher. After sacrificing a solid 66 coupe for its sheetmetal sub-assemblies, I have one solid (and expensive) work in progress!
 

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Watch out for combustion chamber volume though. The combustion chambers are quite a
bit larger on the 351 heads (like 60-61cc) compared to the 54 cc 289 heads. Using the larger
heads will reduce your compression ratio by 1.0, and on a stock 289 running at 8.9:1, you'll be
creating a real dog. You can avoid this problem by having the 351 heads decked by some
amount to reduce the comb. chamber volume.

Rich
'67 C-code 'vert (Dees67)
'69 GT FB (project car)
Milford, NH
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Contrary to popular belief..all 351W heads are the same from 69 through 74..all have 60.4 Chambers..1.84 intakes/1.54 exhausts..in '75 the specs are the same but they have air injector ports designed in..It's a good change to make and will help your engine breathe lots better..mill the heads to regain compression you will lose from the bigger chambers..and you will need a set of head bolts designed for the conversion..everything else will bolt right up..intake/exhaust..etc.

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Rich makes a good point - it might be an opportunity to use those 11.5:1 pop-up pistons you've had laying around *G*! Also, you will need special shouldered head bolts, since the holes in the 351 heads are too large for 289/302 bolts.

Glenn Morgan: 66 GT V-Burgundy Fastback 351w+toploader+9 in. TracLoc. Started out as a rusted-out Chicago-area crusher. After sacrificing a solid 66 coupe for its sheetmetal sub-assemblies, I have one solid (and expensive) work in progress!
 

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One thing I can't stress enough that I've found while checking on years and stuff for my 351W heads on my 302.

CHECK THE YEARS. Especially of the block and your 289 heads. Everyone kept telling me I'd have to mill the heads. I'd lose .5 compression. Turns out it was the other way around. The block and heads for my 302 orignally came from a 1978.. The CC's on those heads was like 69! Therefore, when I went to the 351 heads, the compression goes up.

Check the dates on everything. Check the numbers on everything. Just to be safe.

Rich

(Note, the 1978 302 came from a donor car, not from a Mustang, that's where I think my problems came from. Everyone assumed it was a 1966 302. (if there was such a beast, which I do't think there was)

Rich
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'66, 302-4bbl, Granada disk brakes, etc, etc...
 

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Teebone- are you sure about your numbers. I have a set of 69 351 heads and the measured volume is 64cc. I have also talked to a number of shops, Powerheads for instance, that claim the volume varies from 60-64cc. I would be interested in know where you got your info?

later
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Ford discontinued the shouldered bolts a year or so ago. Edelbrock sells an insert kit for the 351W head that uses the stock 289/302 7/16" head bolts. Edelbrock PN#9680.

Scott
National Parts Depot
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Couple of suggestions: Go to the old forum and do a search on the word "porting". After that, go to this URL:
http://www.fordmuscle.com/archives/2000/05/heads/index2.shtml

Between the 2, they should tell you EVERYTHING you ever wanted to know (and alot you didn't) about 351 heads.

Glenn Morgan: 66 GT V-Burgundy Fastback 351w+toploader+9 in. TracLoc. Started out as a rusted-out Chicago-area crusher. After sacrificing a solid 66 coupe for its sheetmetal sub-assemblies, I have one solid (and expensive) work in progress!
 
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I have C9 351W heads on my '68 289 Coupe. I can't see any reason to use the 351W heads these days (I did mine several years ago). The aftermarket heads are light years ahead of the 351W. Actually, one of the mags did a flow test and the 351W head had worse flow numbers on the exhaust side than the '65 289 heads they tested. I don't really see how with the valves being bigger, but that's what the flow test showed.

One thing that I have not seen mentioned is that the 351W heads will develop "hot spots" if extra holes are not drilled in the water jackets. I did mine about several years ago, so my memory is not that clear, but I remember breaking multiple drill bits drilling those holes. I believe it is two holes per head and I think you just compare it w/ the 289 heads to figure out which holes are missing. But, why go through all this trouble when the aftermarket heads are so far superior. I replaced cast GT40 heads on my Cobra (similar to the 351W) w/ TFS trick flow twisted wedge heads and it really woke the car up. That's why I know the new heads are so much better. Get the aftermarket heads - You won't be sorry.

As a matter of fact, I would be willing to sell my 351W heads to anyone interested and then use the money towards a set of Trick Flows for my '68 Coupe. The 351 heads are '69 (C9 casting), low mileage, w/ mild porting, screw in studs, Crane springs, hardened pushrods, and Manley guide plates.


'68 Coupe, Modified 289 w/ Holley blower
'65 Convertible (future 66 Shelby GT350 clone)
427 Cobra Replica <P ID="edit"><FONT SIZE=-1>Edited by Burk on 04/10/01 11:55 PM (server time).</FONT></P>
 
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