1975 350 intake manifold removal tips

[Ganderson]

I thought I would ask some of you guys with a lot more experience than I for any tips on removing/replacing the intake manifold on a 350. I am swapping a two-barrel carb out for a four-barrel Edelbrock carb. Also swapping intake manifolds.

Thanks for any help!

[demian5]

• Clean the motor really good first.
• Remove the valve covers to make it a cleaner procedure (replace gaskets).
• Don't use the rubber end seals. Use the black silicone (or GMS). Do your best to get a big, fat, one-piece bead of sealant on the front and rear of the block in place of the rubber end seals.
• Light skinning of sealant around the water ports on each side of the gasket.
• Place a tiny bead of sealant below each intake manifold port on each side of the gasket.
• Silicone the threads of the 4 center bolts to prevent oil from wicking up and onto the intake manifold.
• Re-torque bolts after a couple hours then after a couple weeks.

[Ganderson]

Thank you very much!

What is the problem with the rubber seals?

Thanks.

[fatbass]

Originally Posted by Ganderson

Thank you very much!

What is the problem with the rubber seals?

Thanks.

They should be named, "Never seals".

[Ganderson]

Okay thanks!

I'll be sure to pickup some black silicone.

[demian5]

Originally Posted by Ganderson

Okay thanks!

I'll be sure to pickup some black silicone.

Black RTV, sorry.

[terry b]

Make sure to mark your distributor before you remove it. Get the rotor back in the same position. Drain the coolent. You are going to get water and debris in oil so change it and the filter BEFORE you start the engine for the FIRST time. Mark your plug wires. Have fun and take your time you will do great.

[Ganderson]

Originally Posted by terry b

Make sure to mark your distributor before you remove it. Get the rotor back in the same position. Drain the violent. You are going to get water and debris in oil so change it and the filter BEFORE you start the engine for the FIRST time. Mark your plug wires. Have fun and take your time you will do great.

Thanks, I most likely will drain the coolant before I remove the manifold. Needs to be flushed anyways, along with changing the oil and oil filter.

Thanks again!

[demian5]

Originally Posted by Ganderson

Thanks, I most likely will drain the coolant before I remove the manifold.

If you don't you will require an oil change as well as all the coolant will go into the motor...

[Ganderson]

Originally Posted by demian5

If you don't you will require an oil change as well as all the coolant will go into the motor...

Okay. Thanks.

[TCLARK]

Mark your Distributor, very important !

[geezer#99]

When you clean the old gaskets off use some tinfoil in the lifter valley. Poke it into the corners so it stays put. You'll catch all the debris that way.
Also keep track of which bolt holes which bolts came from. A few are shorter so they don't contact the pushrods when they're installed.

[Ganderson]

Thanks for all the great tips! Should start the swap this evening.

[Myoldtruck]

Just did this a few months ago on my 350 also. Watch a few you tube videos on replacing the manifold. I had vacume leaks and the intake did not aling properly, causing oil failed plugs on the drivers side. I had to remove the intake and start over again.

Buy a set of ARP intake bolts with the 7/16" heads, that way you can properly tighten the center 4 bolts by the carb. Besides silicone at the ends of the intake, a light coat around water jacket openings for the intake. I also covered both sides of intake gaskets with indian head sealer. Also a light coat of silicone around the bolts, to prevent additional vacume leaks.

[Ganderson]

Originally Posted by Myoldtruck

Just did this a few months ago on my 350 also. Watch a few you tube videos on replacing the manifold. I had vacume leaks and the intake did not aling properly, causing oil failed plugs on the drivers side. I had to remove the intake and start over again.

Buy a set of ARP intake bolts with the 7/16" heads, that way you can properly tighten the center 4 bolts by the carb. Besides silicone at the ends of the intake, a light coat around water jacket openings for the intake. I also covered both sides of intake gaskets with indian head sealer. Also a light coat of silicone around the bolts, to prevent additional vacume leaks.

Okay thanks! I removed all of the stuff in the way of getting the manifold off. Tomorrow Should be remove and replace. Thanks again for all the help!

[KQQL IT]

Ultra gray rtv has been my go to

[Ganderson]

Got the old manifold off and all of the old gasket removed. Ended up spending some time re-wiring some stuff while I was waiting for parts. I also checked in the glove box for what stuff was ordered from the factory. looks like its a 400ci, with a 400 turbo tranny (3.73). All of the steps were the same for the 400 as the 350.

Thanks again for the help!