things to know about installing a intake and carb

[MEXICANKAMIKAZE]

so i have a 3/4 rwd 79 chevy w/ 350 4 speed w/granny not sure on gearing.... so I got a 2701 intake on eBay that is used but its in very good condition by from what i can tell, no cracks in it and I'm also waiting on my 1406 edelbrock to get here anyway now. so i kinda got an idea on how to do it i watched some videos and had my grandpa explain it to me over the phone but what i haven't found out yet is 1. do i need a torque wrench grandad wasn't to clear on that? 2. can i use the stock intake bolts or do i need edelbrock intake bolts, same with the carb on that can i use the stock q-jet bolts for the new carb or do i need the edelbrock bolts? last one is can i paint my intake with high temp paint or will it just be a waste of time? Thanks in advance

[enaberif]

It isn't a hard job but you will need a few gaskets and some rtv. Yes you need a torque wrench and yes there is a proper sequence.

Just take the old one off and do the reverse to put on.

[Irish_Alley]

You don't need a tq wrench. And you will find there a couple bolts a wrench hardly fits. What I do is buy a intake gasket set and rtv "right stuff" its expensive like $18-$25 for a ez cheese can size of liquid gasket. But it will last a while and they also have a full gun size of the stuff for cheaper. But open the gasket set and toss the rubber gaskets that are in it they go on the end of the intake.  Get stuff to change the oil and a gal of straight antifreeze and some brake cleaner or some sort of cleaner for oil.and its not necessary but on the parts store floor you can buy better metal reinforced valve cover gaskets they will save you some headache and are less likely to leak and you can reuse them. If you go that route you make just get the intake gasket and a thermostat gasket instead of the kit(it might be cheaper)


Fist thing is start taking the things off the intake. And one or both of your valve covers. Take the wires off noting where number 1 plug is at then remove the distributor cap off and note where the rotor is pointing. Then remove ilthe distributor. Drain the antifreeze and remove the upper hose. (Don't have to remove the thermostat housing)

Use a socket and ratchet for the bolts you can get to on the intake. More antifreeze may come out and go into the oil. Clean up the heads where the the intake goes and the part of the block on the front and back side.

Put some rtv on the block where you just cleaned up on the front and back and put a dab on the heads to help Holt the gasket in place. Also add some "right stuff" around the water jackets on the head and intake and wait a few minutes to allow the gaskets to start setting up 5 minutes or so.

Put the gaskets in place try not to slide the around, then carefully set the intake on place again don't let it slide around. Start with the center intake bolts and jump from side to side and work your way to the outside.

Reinstall the distributor with the rotor pointing in the same direction and you took it out. Put the valve cover/s back on and upper hose then plug wires (18436572 you should have this memorized). Put the new carb/gasket on (might need an adapter, I'm on my phone and don't know the bolt pattern or make of the intake). Carb linkage might have some figuring out also.if you have a timing gun this would be a good time to put it at 16° without the vacuum advanced plugged in and then plug the vacuum advanced into manifold vacuum. This allows something like 36° of timing once the engine starts. If you have ping then back it off a little and try again. 

This is the way I do it when you do it so many times on your truck you tend to have a sense on how tight to tighten the bolts and other steps. This may not be the "book" way but its the way I do it and I don't have a problem and you will see the bolts next to carb will be a pain

[ehjorten]

A couple of other things I might add that could come in handy for someone doing this for the first time...

1) Take pictures of related components on the intake before you start your teardown.  This can be valuable if you can't remember how something went back together.

2) Check bolt length for proper length, especially on your thermostat housing.  Because this is an aluminum intake, if the bolts are a little short you can easily pull the threads on the aluminum and then you will have to heli-coil them to fix it.

3) You can paint the intake, but if you don't prep it really good, it is going to start flaking off of the aluminum.  Aluminum really needs to be cleaned and etched prior to painting.

[Irish_Alley]

Oh yeah since you're changing intakes you need to take the thermostat housing off lol but I use mine as a handle for the intake

[bd]

For standard hex head bolts use a 9/16", 3/8 drive flex-socket and an 8"-10" extension.  Since you haven't done an intake swap before, better to use a torque wrench to tighten the intake bolts - it is easy to under-tighten the bolts or tighten them unevenly, resulting in vacuum leaks.  Follow the factory torque sequence illustrated in the 1979 Service Manual page 6A4-11 (Fig. 6A4-9), torquing in three distinct steps (arbitrarily, 60%, 85%, 100%).  Recheck the final torque (30 lb-ft) a couple of times through.  When using a torque wrench, apply a steady, s·l·o·w pull.  As ehjorten recommended, check for adequate penetration of any bolts threading into the aluminum manifold.  But, in addition, check the protrusion of the intake bolts through the intake flange and out the opposite side.  Aluminum intakes generally have a thicker flange than cast iron.  Make sure you have 1/2"-5/8" of bolt thread protruding past the intake gasket flange and into the cylinder head or you might pull threads out of the head.  Standard SBC intake bolts are 1.25" under head length; BBC engines use 1.5" UHL bolts.  The 1.25" long bolts may not provide enough thread bight, especially if they also retain throttle brackets and such.  However, it is possible to use bolts that are too long if they bottom in the end holes or extend all the way through the cylinder head flange.  Center bolts that are too long run the risk of colliding with valve pushrods.  So, pay close attention to bolt length.  Finally, chase all of the threaded bolt holes with a bottoming tap and blow them clean with B-12 and compressed air.  If reusing bolts, wire wheel the threads.  Then coat all of the intake bolt threads with a good Teflon paste sealer, such as ARP Thread Sealer.  The sealer lubricates the threads and prevents oil from wicking up onto the top of the manifold from the valley.

The Edelbrock 1406 uses the same length mounting bolts at all four corners.  You may be able to reuse the QJ rear bolts, but will have to procure two additional similar bolts for the front.  While you have the thermostat hosing off, inspect the gasket surface for flatness.

[MEXICANKAMIKAZE]

A couple of other things I might add that could come in handy for someone doing this for the first time...

1) Take pictures of related components on the intake before you start your teardown.  This can be valuable if you can't remember how something went back together.

2) Check bolt length for proper length, especially on your thermostat housing.  Because this is an aluminum intake, if the bolts are a little short you can easily pull the threads on the aluminum and then you will have to heli-coil them to fix it.

3) You can paint the intake, but if you don't prep it really good, it is going to start flaking off of the aluminum.  Aluminum really needs to be cleaned and etched prior to painting.

ill probably get the bolt kits for the carb and intake and what do you mean by etched? the intake that i got is slightly used but the guy sprayed it grey don't know how he went about it but should i sand it and respray some high temp paint?

[Irish_Alley]

Scuffed up?

[MEXICANKAMIKAZE]

Scuffed up?

no the top is CLEAN but the bottom is a little dirty

[enaberif]

LOL don't worry about the bottom. Just clean the top off if you want.

[bd]

...what do you mean by etched?...

Paint sometimes doesn't adhere well to shiny fresh aluminum and can flake.  In context, etching is a chemical or mechanical process to slightly roughen a surface by removing a tiny amount of surface material to improve bonding of the paint.  It sounds like this will not be an issue.  If you wish to paint the manifold, use high temp engine paint.  It is less susceptible to damage from gasoline and automotive chemicals once it cures.  Avoid painting any gasket surfaces.

[rich weyand]

The issue with aluminum is it forms a thin surface oxide that doesn't adhere well.  Either you need to clean the oxide off (mechanically or with an etchant), or use a paint formulated to do a better job of reaching through the oxide to the aluminum underneath.  Sometimes the best thing is an aluminum-specific primer, to give your paint of choice a surface to adhere to.

[MEXICANKAMIKAZE]

since I'm taking the value covers off should i do anything to the heads?

[enaberif]

Clean out the crud from under the valve covers and put some rags down and take some fine sandpaper and lightly go over the surfaces for the intake manifold and make sure there is no old gasket material.

I used like 300 grit sandpaper with some acetone

[MEXICANKAMIKAZE]

So i've been busy with college and life an haven't gotten to this yet but i am this week i ordered a gasket since the parts store is charging way too much. my question is do i need edelbrock intake bolts or can i use the ones from GM thanks in advance