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Discussion Starter · #1 ·
I review the Dart heads again yesterday and I saw something that concerns me a little.

Once the rocker arm bolts were installed on the heads, the bolts penetrated into the intake passage ways.

I didn't get picture of it and I hope I can best describe it.

If you were to look down the intake passage ways in the heads, you can actually see a 1/4 inch of the bolts.

My concerns were, could this create leaks? Air fuel or oil?

Are these bolt patterns and design normal? It just looked kind of weird seeing bolts sticking through intake passage ways.

Below is an old picture but I've drawn arrows to the above referrence.

Hope this makes sense.

Thanks.

Bolts seen in intake passages
 

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i guess if the heads are big they have to cut into somewhere. Like if they made the intake passages say 1/8 of and inch larger that stock they can't stretch the heads so they need to cut into other places. That happens on the 4 bolt main 400 blocks the main cap bolts pertrude into the bottom of the cylinder because the bore is so big. Well thats my theory but im nor sure…
 

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It would seem to me the best thing to do would be to shorten the bolts to where they don't enter the ports and use some sort of Loctite product on them to seal against any leaks. It should work. Just my .02

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68 Malibu B&M blown 350, TH350 with 10" converter and Gear Vendors overdrive, 12 bolt-3.90 gears
69 CST Pickup original 396, TH400 factory AC/PS/PB
99 Harley Dyna Wide Glide
91 Sportster 883- now a 1200!
 
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That's not all that uncommon with aluminum bbc heads. The most important thing is to make sure the stud is ground off so that none of the threads actually protrude into the port.

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Malibumotorsports
79 Malibu, 414 ci BBC, 3550 lbs.
10.75 @ 125 mph, 1.49 60'
 

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Never had this problem and don't really know diddly about it, but, I would do what Todd says and seal it with some blue lock-tite.

JM 0.002
 

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your concern is well founded. Intake flow obstrution (even in such a big runner) is a bad thing.

I'd grind away the protruding stud threads after it is well seated. I'm not sure what you would seal the threads with given the steel/Aluminum mating. Just grind away as one would open up a penut port head. If you do "trim" the studs out side of the head be sure you do the "reverse nut" method so the threads come out clean. One bad thread and it's hello-hela coil.

just a thought: If you do shorten the bolts outside the head, maybe the "lack of metal" would cause just as much turbulance as the proitruding metal. What do they call it, a venturi?


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FYI, loctite will seal them up. However, if you grind the bolts down afterward, the heat may affect the loctite.

Mike's got a good point about flow - maybe some JBWeld or something once they are ground/cut off will finish off the intake walls to make the flow the way it should be.
 

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Discussion Starter · #8 ·
Wow, thanks for your information.

I appears this set up is normal.

And, it appears that the suggestion is to ground-off the protruding bolt ends.

Thank you all!
 

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i'd agree with the "lack of metal" theory too, i'd grind them out of the head at the correct angel of the port (assuming they are on the sides of it or near the corners) and then wire clean them up (kind of like an exhaust manifold bolt). not a lot of threads on the end but will mimic the shape of the runner

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wow, I just gave Tonyr some maybe good advice, GO FIGURE


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Grinding the bolt flush to the port is excellent advice...no sense in creating an obstruction/diversion with all the air that motor will be moving


How bout some anti-seize lubricant? Should use that stuff when using steel bolts into aluminum material anyway...(ever try removing one of those hex plugs outta an aluminum manifold) I'd imagine it'd create just as good seal as loctite...?

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