Milling Intake to fit new engine

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340sFastback

340sFastback

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Got a 414 SB with Eddie heads. Heads were milled to 62cc and block was decked to 9.588". Intake is an LD340. I am going to run Felpro 1213 intake gaskets which are .060" thick and compress to about .050". With NO gaskets on I can get all the bolts in by hand but two are tight. All the bolts ride right up against the lower bolt holes indicating the intake is slightly too big even without any gaskets (see picture). Looks to me like each side should be milled minimum .060". But I believe .080" or so would probably leave the bolt right in the middle of the hole once torqued. How much should be milled off to make this intake fit? I prefer not to mill the intake side of the heads.

IntakeBoltFitment.jpg
 
I don't know why you wouldn't mill the heads. That would make any intake fit the engine easy. Reguardless, id mill both sides of the intake .005 shy of the .060. Use ethier a drill or dremel to open up the intakes bolt holes.
 
I'm with Rumble, the heads are not stock dimension anymore so why not take it one step further and mill the intake faces so then you can use any intake you want in the future. Who knows, you may not like the LD340.

Terry
 
If it were me, I'd go .070 and checkthe fit. I also agree, that intake may be swapped afterword, and the time to make teh engine easy to retrofit parts to is now. pull the heads and have them cut would be the optimum.
 
I see this all the time, shops milling away but never correcting the intake face.
I have the same problem with my 344, but at least I had a milled weiand sp sitting around [for 10yrs] that I finally got to use once I found what they DIDN'T do.

If aint been fired/installed in the car MILL THE INTAKE FACE OF THE HEADS.
Don't make that rare intake a one off piece.
 
Well said, and thats theproblem. Once your done with a milled intake, how many people can use a milled intake.

At least you can said the heads are properly milled and willaccept any intake cause there done right.
 
moper said:
If it were me, I'd go .070 and checkthe fit. I also agree, that intake may be swapped afterword, and the time to make teh engine easy to retrofit parts to is now. pull the heads and have them cut would be the optimum.
Click to expand...

Dave, Isnt the intake on my motor milled ? I have another intake I would like to use, any clue how much I should have milled of the intake surface of the heads ?
 
I had the local shop mill .075" off each side of the intake. I'll be picking it up tomorrow.

I do agree with everyone that milling the heads is the correct way to do it but the engine is together and I need to get it running.
 
Got it back with .075" milled off each side. With gaskets in place it fits perfectly and I can spin all the bolts in by hand!

I also had the shop trim the plenum divider down some to increase top end.

IntakeTestFit_Shrunk.jpg


IntakePlenum_Shrunk.jpg
 
Is the LD340 a decent manifold? I've got one sitting on my 318 and see it pop up in posts from time to time...
 
HevD said:
Is the LD340 a decent manifold? I've got one sitting on my 318 and see it pop up in posts from time to time...
Click to expand...

It is comparable in performance to a new Edelbrock RPM so yes it is a very good intake.
 
HevD said:
Is the LD340 a decent manifold? I've got one sitting on my 318 and see it pop up in posts from time to time...
Click to expand...

A nice old unit that is in the MP engines book with tricks and mod tips for racing.
 
340sFastback said:
Got it back with .075" milled off each side. With gaskets in place it fits perfectly and I can spin all the bolts in by hand!

I also had the shop trim the plenum divider down some to increase top end.
Click to expand...

He had it milled.

Engine looks great and should haul ***.
 
Adam, it was cut a lot... I want to say at least .050/side. I dont recall 100% tho.
 
340...lol. Adam has a 360 I did for myself a while ago... That was what I was referring to.
 
Thanks Dave, Sorry for the confusion 340.

I need to get this car painted so I can bolt stuff back together and stop thinking, LOL
 
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