Author Topic: ‘78 W72 4 Speed header installation tips.  (Read 776 times)

Billablehours

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‘78 W72 4 Speed header installation tips.
« on: March 09, 2023, 06:28:24 AM »
Hello all.

I have a 1978 W72 four-speed car that has Hedman headers on it. I have developed a header leak and decided to go ahead and replace the headers since they are not ceramic coated. The old headers fit fine but are old and I figured it was time.

I decided that replacing them with the exact same headers was the easiest way to go. I am looking for any tips that you all have for installation. I do have access to a lift.
Fastener recommendations? Gasket recommendations? Tips on how to get them in place etc?.

I don’t need any recommendations on different header brands.   I already bought these these.

5th T/A

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #1 on: March 09, 2023, 08:56:13 AM »
It’s been many years, but I have installed headers on a variety of cars and it was usually a pain in the @ss. Mostly did it with out a lift with the car on jack stands. Almost always had to loosen up engine mounts and use a Jack with block of wood on the oil pan to raise the engine. Before doing anything disconnect the battery. Often had to remove the starter motor anyway and is was sometimes a challenge to get the starter back in. On Pontiac and cars with a rear mounted distributor, remove the distributor cap and watch clearance between distributor and fire wall as you raise the engine. Obviously start all bolts on the flange before tightening any up. There are specific gaskets for headers, usually thicker. Also specific bolts with smaller heads and some with locking mechanism as header bolts like to loosen up.

It’s probably 35-40 years since I have done this so hopefully someone with recent knowledge can offer better advice.
1980 T/A with a Pontiac 461

Gone but not forgotten;
1973 T/A 455
1975 T/A 400
1978 T/A W72
1982 T/A cross fire injected

Two wheel toys;
2014 Harley Ultra Classic Limited
2013 Honda CB1100
2010 Yamaha Vmax
1982 Yamaha Seca 750

phil400

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #2 on: March 09, 2023, 11:23:02 AM »
Ive installed and removed Headers several times on these cars,  agree with what  5th T/A posted only way Ive found is Headers go in from the bottom, gonna have to remove engine mount bolts, and raise the engine, may or may not have to remove the oil filter housing, and z-bar clutch linkage and starter I think.

A friend of mine has Had good very service with Percy's header gaskets, I helped him install headman header.
78 T/A 4 speed, original paint, match #s, mine since ‘99, 3rd & final owner as long as I'm alive.
77 T/A sold
85 Monte Carlo SS sold
83 Mustang GT sold
https://youtube.com/@classicdriversgarage108

Billablehours

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #3 on: March 09, 2023, 08:27:25 PM »
Thanks

tajoe

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #4 on: March 11, 2023, 11:11:48 PM »
Hedders on a Pontiac is quite a bit more challenging, than most others. Mainly cause of the exhaust port angling towards the ground. That's why I believe in most street applications the RA manifolds make more sense. For many benefits. But if you're lookin for that all out bit of necessary power, (and image), hedders for performance reign. Nothing like the sound of a set of open hedders on a sunny spring day. :-)
 
The 1st thing needed for Pontiac V8 hedder installation, is a yard of patience. (Seriously) Especially if you're not a professional. Next will be some very long 3/8ths extensions, and possibly a wobbler to fit them, for getting at the back cylinders from below. That way you can use a ratchet, rather than open end wrench. And have some stubby open ends, and maybe even some cheap Chinese ones, that you can bend a slight angle into. And your flange gasket, you can cut into 3 sections for each side. Separate the frt, middle and ends from each other. Then slot the bolt holes under the ones that aren't already. And the bolts should be specifically short hedder bolts, 6 pt 7/16th, with the small diameter built in washers. (Not sure if 3/8ths size heads are available, but would be better).

Depending on the make and fit of the hedders chosen, will determine how many accessories you'll have-ta remove, to get them up into place. Start with the frt bolt 1st, then the fwd bolt on the rear cylinders, and only catch them by a thread or 2. That was the easy part. Next you'll need-ta squeeze in the rear bolts on the frt cylinder, and the rear bolt on the 5-6 cylinder, where the tube is bent right smack in the way. Twist them in  a few turns also. This is where patience, and the short bolt really shines. And finally the rest can be installed, from above and below.
Next is when you just simply slide your individual gaskets in from above, and not have-ta worry about alignment problems with bolts holes, if you didn't separate them. Once they're in, you can begin tightening all bolts, remembering that the ones above the bent tubes, (1-2, + 5,-6) will need-ta be tightened simultaneously 1st, then the rest randomly.

My preference "ust-ta-be" using the factory metal exhaust gaskets in the Fel-Pro kits, cause they would last yrs, before rotting out, where the Mr.Gasket paper ones would blow out every season. Course, this was when we drove our cars every day, as daily transportation. Car-port queens might last quite a bit longer.

That's about all the basics I can remember, but with todays new aftermarket stuff, maybe things have changed, hopefully for the better. Hope some of this helps, along with the other advisors.
"You can sell an old man a young mans car,
but you can't sell a young man an old mans car"
                                       Bunkie Knudsen
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Re: ‘78 W72 4 Speed header installation tips.
« Reply #4 on: March 11, 2023, 11:11:48 PM »

gstrandfarm9420

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #5 on: March 13, 2023, 08:28:49 PM »
I would make sure you are happy with your starter if using a OEM, because it's no fun to change later. Another thing that might give you trouble is the steering column ignition lock linkage, it's been awhile but I think you can just tweak it and it will work, although a lot of people gave up and took them off. Nice to have if you want backup lights and locking steering wheel without re doing the wiring. ( If it's an automatic) Myself I went with Ram Air manifolds after many years of maintaining headers on a variety of vehicles. Good Luck!

81Blackbird

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #6 on: March 14, 2023, 02:55:01 AM »
Remflex for gaskets.

http://catalog.remflex.com/

Wallington

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #7 on: March 14, 2023, 04:03:26 AM »
Back-up lights are more critical than ill-fitting headers.

nUcLeArEnVoY

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Re: ‘78 W72 4 Speed header installation tips.
« Reply #8 on: March 14, 2023, 06:09:27 PM »
You're going to have to raise the engine up to get clearance, but it can be done.

I drilled out dead-on-balls center 3 snapped exhaust manifold bolts broken flush to the head on the driver side when addressing an exhaust leak, all with the engine still in the car. Couldn't have done it without a centering jig I rented called Beydler's manibolt driller. Numerous raising/lowering the engine, multiple angle drills including a super low profile threaded shank attachment meant for aircraft, high quality cobalt drill bits and taps from McMaster-Karr, a custom-fabricated low-profile ratcheting tap wrench, blood, sweat, and tears but I pulled it off with not a single helicoil insert - all original female threads in the head retapped and preserved.

If I can do that, you can install headers. 
« Last Edit: March 14, 2023, 06:10:59 PM by nUcLeArEnVoY »
1979 Trans Am 400/4-Speed W72/WS6 - Starlight Black Hardtop

Re: ‘78 W72 4 Speed header installation tips.
« Reply #8 on: March 14, 2023, 06:09:27 PM »
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