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Can I use Automotive heads? |
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KooK 
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Joined: February-10-2014 Location: Iowa Status: Offline Points: 143 |
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 Topic: Can I use Automotive heads?Posted: May-04-2017 at 5:07pm |
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So after looking, my 79 Mustang 17 has D8 heads. I was wondering (while I'm rebuilding the engine anyway) if there would be an issue using E7 heads from an EFI Mustang? I'm not sure what all is different between marine and automotive in this area.
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Dreaming
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Joined: May-21-2010 Location: Tacoma, WA Status: Offline Points: 1870 |
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Posted: May-04-2017 at 5:15pm |
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nothing special about heads, except the exhaust configuration needs to match. going to EFI might be a problem though, you'd need to account for where the injectors go. that may be in the intake in your particular engine, but you should be sure before running down the head swap road.
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KooK
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Posted: May-04-2017 at 5:25pm |
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Actually, I was just stating the heads themselves came off an EFI Mustang, I'm keeping mine with a carb for the time being.
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KENO
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Joined: June-06-2004 Location: United States Status: Offline Points: 11061 |
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Posted: May-04-2017 at 5:44pm |
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If the heads were free and in good shape then sure.use them
The E7's have a slightly smaller combustion chamber, same size valves as the D8's. They called them fast burn combustion chambers in the E7's. A little more modern design. If you have to spend money to get them, you could do better with GT40P heads One difference is that marine heads have brass freeze plugs in them as part of the marinization process. If you leave the steel plugs in they'll eventually rust out some number of years down the road when you least expect it. The seats and the valves at least in these Ford heads are the same material whether they're auto or marine |
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KooK
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Joined: February-10-2014 Location: Iowa Status: Offline Points: 143 |
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Posted: May-04-2017 at 6:16pm |
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The only reason I was looking at the E7's is because the guy wants $25 for the pair, and I'm thinking hell, $25 for even a small upgrade isn't terrible.
Although while you were saying that, I was also looking at GT40 heads just to look at them. Although information is all over the place. I'm being told GT40P heads require a different exhaust setup and that I should stick with f3ze casting GT40 heads. If I know the port spacing, stud spacing, and everything is the same, that I can bolt up my intake and exhaust manifolds that I currently have, I'd rather have a GT40P, or at least a GT40. I never realized how cheap these things were. Edit: So what I'm finding is the GT40 and GT40P heads are pretty similar, the GT40P heads just have a different spark plug angle which may interfere with some exhaust manifolds. That and the GT40P isn't plumbed for an EGR because it's in the intake, while the GT40 EGR was stuck into the heads and would need to be blocked off for my application. It seems like a lot of the things are the same, I wouldn't mind fitting a set of GT40P heads, like I said, as long as I know 100% my stock intake and exhaust will bolt up to them. |
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GottaSki
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Joined: April-21-2005 Location: NE CT Status: Offline Points: 3359 |
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Posted: May-04-2017 at 6:27pm |
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The GT40P exhaust issue had been non issue with marine ex manifolds, On autos there are some header/plug access and interference scenarios, but don't apply to your case. They do use a different reach spark plug.
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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Gary S
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Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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Posted: May-04-2017 at 6:30pm |
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Ok Ken you've been told before that they are core or casting plugs. Now go sit down for a time out!
On my original heads I rebuilt D8oe's or something the rebuilder forgot and put in steel ones, in my fresh water they lasted around 20 years before the rear ones rusted thru. When I bought the 40p's from tristate they said they didn't have brass either so when it comes time I'll replace them too. As for different manifolds PCM's and Holman Moody's fit just fine. It's only a problem in automotive because the exhausts go down past the spark plugs. |
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Gary S
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Posted: May-04-2017 at 6:35pm |
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Gt40's have cracking issues p's don't. P's need to have the head bolts holes to be drilled for the 351 size - 7/16 to 1/2" if I remember
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KooK
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Joined: February-10-2014 Location: Iowa Status: Offline Points: 143 |
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Posted: May-04-2017 at 7:02pm |
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Looks like I'll be picking up some GT40P's next week, thanks guys!
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KENO
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Posted: May-04-2017 at 7:35pm |
OK Gary During my time out I went and sat on the FLOOR of my boat and thought about Pete but while I was doing that I noticed that the SOLE of one of my shoes was in pretty bad shape  Gotta dig a little deeper and see if the rest of the shoe is OKI'm only on about year 12 of some steel plugs, so I got a while to go I guess For KooK With GT 40P's the plug changes are easier like Gary and GottaSki said. They point straight out instead of being angled toward the exhaust runners and since you have a 302 there's no drilling necessary.for head bolts. Plugs are Autolite 764's or Autolite 104's are a substitute. 764's are funny looking because they're only threaded halfway. The 104's are the same thing with normal looking full threads. |
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Gary S wrote: