Tips/steps to take before removing intake manifold

kmorefield

Member
Jan 4, 2020
62
6
8
carb, intake, and other parts and pieces in prep for installing the new intake and efi. Does anyone have tips or advice for removing all of the parts
and intake? I plan taking a lot of pics first. Does a guy just dive in ands start removing things one at a time? I plan on cleaning out any
“cookies” that I find below the intake. The aluminum intake has no exhaust crossover, so I won’t have to worry about blocking that off….
I’ve got a leak in one exhaust manifold gasket so will tackle that as well… any words of wisdom or gotchas to look out for? This is for a 1975
455.

Thanks,
Ken
--
1975 - 26’ Eleganza II
Unsure of what upgrades may have been done. I'm working on sorting that out in the coming months.
Ken Morefield - Redding, CA
 
> I recently purchased Howell EFI with ebl and computer controlled distributor and an aluminum intake with gaskets. I’m hoping to start removing
> carb, intake, and other parts and pieces in prep for installing the new intake and efi this weekend. Does anyone have tips or advice for removing
> all of the parts and intake? I plan taking a lot of pics first. Does a guy just dive in ands start removing things one at a time? I plan on
> cleaning out any “cookies” that I find below the intake. The aluminum intake has no exhaust crossover, so I won’t have to worry about
> blocking that off…. I’ve got a leak in one exhaust manifold gasket so will tackle that as well… any words of wisdom or gotchas to look out
> for? This is for a 1975 455.
>
> Thanks,
> Ken

Ken, I sent you a private message.
--
Randy & Margie
'77 Eleganza II '403'
Battlefield, MO
 
Thanks Randy. I've got it printing out now. This should get me most of the way there with regards to the efi install. I may be bothering you with
some questions or advice as I go!

Ken
--
1975 - 26’ Eleganza II
Unsure of what upgrades may have been done. I'm working on sorting that out in the coming months.
Ken Morefield - Redding, CA
 
I just installed the aluminum intake manifold this past spring. I choose to use blockoff plates even though the manifold has no crossover passage.
The heat of the exhaust was sure to burn up my nice new intake manifold gasket and ultra black sealer without it. Also the nipple for the coolant
hose to the heater at the passenger rear of the intake manifold is a smaller size on the aluminum manifold than on the cast iron one. I couldn't
remove the old one anyway so a new smaller one was fine.

Also the rear A/C mount didn't line up with the drilled and tapped spot for it on the intake manifold. Otherwise everything went well.

Had to do the install twice however. First time tried to get by on one tube of ultrablack. Got an oil leak at the front of the manifold. Without
the gaskets used in the front and the back, there is quite a gap to fill with sealant. Second time around used two tubes of Ultrablack and the
manifold is oil tight still after 3,000 mi.
 
If by chance you aquired the intake from us, I need to know so we can
correct it. as we remachine them to fit not only the bracket, but the
carburetor ports.

> I just installed the aluminum intake manifold this past spring. I choose
> to use blockoff plates even though the manifold has no crossover passage.
> The heat of the exhaust was sure to burn up my nice new intake manifold
> gasket and ultra black sealer without it. Also the nipple for the coolant
> hose to the heater at the passenger rear of the intake manifold is a
> smaller size on the aluminum manifold than on the cast iron one. I couldn't
> remove the old one anyway so a new smaller one was fine.
>
> Also the rear A/C mount didn't line up with the drilled and tapped spot
> for it on the intake manifold. Otherwise everything went well.
>
> Had to do the install twice however. First time tried to get by on one
> tube of ultrablack. Got an oil leak at the front of the manifold. Without
> the gaskets used in the front and the back, there is quite a gap to fill
> with sealant. Second time around used two tubes of Ultrablack and the
> manifold is oil tight still after 3,000 mi.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>

--
Jim Kanomata ASE
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502
 
Take pictures of the current installation. It will help you when you go to put all the vacuum lines back in place. Also, label the vacuum lines,
trans, advance, PCV. brake, etc. Just get everything as clean as you can. Use a shop vac to clean out the lifter valley. I used Dick Paterson's
gasket set with the SS block-off plates. It is the proper thickness, and I felt that the plates would protect the aluminum manifold from the extreme
exhaust heat.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
Solar battery charging. GMCSJ and GMCMI member
 
In terms of the exhaust block-off plates, I like to use the old original metal intake gasket/drip tray. I trace the opening on a nice relatively clean area and cut two rectangular plates with tin snips. Just being cheap but effective.

James

1976 Birchaven 23 footer rear bed 455
1976 “unknown” 26 footer rear bed 455

>
> Take pictures of the current installation. It will help you when you go to put all the vacuum lines back in place. Also, label the vacuum lines,
> trans, advance, PCV. brake, etc. Just get everything as clean as you can. Use a shop vac to clean out the lifter valley. I used Dick Paterson's
> gasket set with the SS block-off plates. It is the proper thickness, and I felt that the plates would protect the aluminum manifold from the extreme
> exhaust heat.
> --
> Carl Stouffer
> '75 ex Palm Beach
> Tucson, AZ.
> Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles,
> Solar battery charging. GMCSJ and GMCMI member
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
 
I built a little gantry between the front seats and used a come-along to aid in removal and replacement.

Pictures, labels, anything that you can group in a little sandwich bag with a label (carb bolts, cruise control, etc.) makes it easier to discern.
Especially if you think it will be a two day project, life intervenes, and you come back three weeks later asking "where did this go?"

--
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
 
If you do use the "turkey tray" for block-off plates, be sure that you
measure the thickness of the metal. If it is not the same thickness as the
Paterson gasket, my recommendation would be to NOT use it. The block off
plates should be exactly the same thickness as the gasket when it is
compressed by tightening the manifold bolts. I would not recommend
inserting the block-off plate between the manifold and gasket without the
gasket cut away to allow for the plate.
When I install those manifolds, I invert the intake manifold on a clean
work bench, super clean the gasket surfaces with carb cleaner, then spray
the manifold and the mating surface of the gasket with 2 coats of "Hi-tack"
gasket sealer. When the sealer tacks up to the touch, place the gasket
precisely onto the manifold as well as the block-off plate, drop some bolts
through the hold down holes, and leave it alone overnight. I use my cherry
picker to lower the intake manifold onto the engine. Use a bead of sealant
around all the water passages, as well as the end dams on the block. Let
your sealant skin up then carefully lower the manifold onto the block. I
use tapered punches in all 4 corners of the manifold to align it. Then,
place the bolts in the holes and using the torque sequence from the Olds
manual, torque it down. Then, leave it alone overnight to make sure the
sealant cures.
Alternately, if you are using the neoprene end dam seals, religiously
clean the block surfaces before placing those seals in place. Don't use any
goop here. It will cause the seals to squiggle out of place. Do it once, do
it right, and you will have an engine that is oil, vacuum, and water tight,
and block-off plates that stay put for as long as you will need them to.
Get a bit sloppy here, and you will regret it, and have to do it all over.
Jim Hupy
Salem, Oregon

> In terms of the exhaust block-off plates, I like to use the old original
> metal intake gasket/drip tray. I trace the opening on a nice relatively
> clean area and cut two rectangular plates with tin snips. Just being cheap
> but effective.
>
> James
>
> 1976 Birchaven 23 footer rear bed 455
> 1976 “unknown” 26 footer rear bed 455
>

> >
> > Take pictures of the current installation. It will help you when you
> go to put all the vacuum lines back in place. Also, label the vacuum lines,
> > trans, advance, PCV. brake, etc. Just get everything as clean as you
> can. Use a shop vac to clean out the lifter valley. I used Dick Paterson's
> > gasket set with the SS block-off plates. It is the proper thickness,
> and I felt that the plates would protect the aluminum manifold from the
> extreme
> > exhaust heat.
> > --
> > Carl Stouffer
> > '75 ex Palm Beach
> > Tucson, AZ.
> > Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive,
> Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American
> Eagles,
> > Solar battery charging. GMCSJ and GMCMI member
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
 
> In terms of the exhaust block-off plates, I like to use the old original metal intake gasket/drip tray. I trace the opening on a nice relatively
> clean area and cut two rectangular plates with tin snips. Just being cheap but effective.
>
> James

James,

If you are going to use the embossed steel gasket and block the exhaust cross-over you do not need the valley pan. The entire purpose of that pan was
to keep the lube oil that the cam kicked up from splashing onto the hot cross-over that will no longer be hot.

Another issue that Dick Paterson kit has covered is that the compressed thickness of the intake gasket material has to be really close to the that of
the block off plates. If you are going to cut your own block-ff plates, I strongly suggest that you make them out of a stainless steel of 312 or
better.

Good luck with this and let us know how it goes.

Matt
--
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
 
Jim,

Rest assured that my aluminum intake manifold was not purchased from Applied GMC.

I bought this many years ago from the Coop when they first became available. It might have been an early production model that hadn't been fine
tuned. As far a I can tell, the Carb fitted the manifold well without any obstruction to the throttle plates.

When I had the carb rebuilt by Coop several years ago, it came with a new thick gasket to prevent boiling over from the intake manifold crossover
heat. The engine actually had less power than before the rebuild of the carburetor. I finally found that that thick gasket was cut improperly and it
was interfering with the secondary throttle plates from opening fully. After I trimmed this, my engine had like new power.

What is the carb mod on the intake manifold that you do? I am always looking for more power, if I neglected a machining error.