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intake manifold replacement

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Old 07-25-2016, 01:56 PM
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ndirishr1
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Default intake manifold replacement

I'm pulling the intake on my 68 stock 327 cu 350hp 4 speed to replace the gasket and clean and paint... I've done this years ago so I'm too dumb to be afraid but if anyone can point me to some "how to" so I don't screw it up I'd appreciate it... the engine is stock but the intake is an edelbrock polished #2011 and the carb is a replacement quadrajet edelbrock 1901... something to guide me so I get the distributor out and back in correctly and get the seals right would be appreciated... also an opinion, I replaced this many years ago and used the edelbrock without the oil fill tube, discarded the fill tube and have been adding oil through the valve cover... never thought about this until now but could getting rid of the oil fill tube version have caused enough back pressure to create a minor antifreeze leak in the seal on the intake? thanks, been there and done that but I'm old now and have forgotten most everything but my name :<)
Old 07-25-2016, 02:26 PM
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427Hotrod
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The easiest way to handle the distributor is to bump engine around until the rotor is pointing at a reference point that isn't going to move. The wiper motor, a fitting on intake or make a mark on firewall. Doesn't matter...just so you know where it's at. Pull distributor and replace gaskets and then drop distributor right back in same spot it was. If you don't turn the motor while intake is off, it will drop right back in. Pay attention to the vacuum canister also so you get it back in right spot. If motor hasn't been turned it's only going to "drop" in at two spots. One with the rotor pointing at the mark..and the other with it 180* the other direction.

Most people use silicone on the end rails. The "Right Stuff" or any of the gray or black silicones work well. Make sure it "likes" oil...some only work well with water. Put a bead across each end rail of block after cleaning and let it tack up for a few minutes. Then drop intake in place. Trim off excess after it dries. I use Permatex Aviation glue (parts stores have it) and brush it on around the intake and water ports on the heads...and then on the gasket area that mates intake around intake and water ports.

After it's run and warmed up a couple of times and cooled down...go back over the bolts to snug them up and you're done. Well...you have to set the timing...but you knew that.

Do your valve covers have any breathers? PCV valve? If the only thing you had was the oil fill tube...you've got no way for crankcase pressure to vent. Won't cause coolant leaks usually, but will cause lots of oil leaks.

JIM
Old 07-26-2016, 12:28 PM
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go to the edelbrock website and see If they recommend gasets on the block for your intake. Mine did not and using them will force them out and cause oil leaks. You can also look at themanifold when you take it apart to see if you used them originally. You'll need t a torque wrench as well so you dont strip the heads when you bolt on the manifold. If you do strip it then you can fix it with a helicoil kit to replace the threads.

For the disributor I cut the top off an old distributor cap to use when adjusting valves. It will help to line it up at a specific cylinder then take a pic so you can't forget.
Old 07-26-2016, 12:53 PM
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69Vett
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bump the engine to #1 plug wire before you tear down, write down the firing order unless you know it by heart, original intakes have it embossed on them.
use a sharpie to mark the on the dist. base, pointing to exact physical location, edge or screw hole.
the sharpie mark will allow you to return the timing exactly back to original.
setting #1 will ensure you get the timing orientation correct, and will assist if you get lost putting back together. use masking tape to block off air/fuel passages into the cylinder head as soon as you get the intake off, leave it there until your ready to assemble.
if your changing intakes make sure the height is not too tall to fit under corvette hood.
if your in warm climate use the intake gasket set, and install the hot air block off tins.
this will result in cooler carb. which you want unless you live way north.
toss out rubber intake end rails and use good silicone sealer.

I put a dab of sealer on all intake bolts to prevent any leaks.
this intake is painted, if you do not want to see rusty head side rails where intake bolts on.
I use old gaskets for paint mask, to paint exposed head surface only, do not paint sealing surfaces.


Last edited by 69Vett; 07-26-2016 at 01:03 PM.

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