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1968 Pontiac Firebird 350, which headers?

18K views 25 replies 8 participants last post by  Mr. P-Body 
#1 ·
Hi there,
So I got alot of help from the folks on here with my future transmission installation and at the same time as i do that i think im going to get rid of my cast iron manifolds.

within my budget is either the hedman 28140 or the hooker 4902. do you know which one fits better. my car is a 1968 pontiac firebird with a pontiac 350, it is an automatic with power steering. i installed the original cast manifolds myself which were not too bad considering how hard a few bolts were and how heavy the suckers were, i heard the aftermarket headers are much lighter and will increase power substainually since the cast manifolds are very restrictive. my main concern is how easily they will fit.

Thanks in advance
 
#2 ·
If your main concern is the ease of the header fitting, either Hedman or Hooker are in the top brand names for headers, in my experience, the amount of power gain when installing headers is going to be reflected with how much exhaust your pushing through the engine. For example, you would get a bigger increase in performance if you had your heads ported and polished than if ran stock heads because your engine can produce more flow...if your running a Pontiac 350 with a 2 bbl Carb, you would get less performance from your headers than if you where running a 4 bbl Carb with an upgraded camshaft.

I've used both Hedman and Hooker on Pontiac engines and have had good results.

Hope this helps.

Ray
 
#3 ·
pontiac engines by nature are harder than most to put headers on. because of how far the exhaust ports go..
I've had good luck with hooker.. both brands you've listed have made headers for this car for decades..
just remember most of the headers will have tube sized for 400-455 cid..
don't get the biggest tube headers..
 
#5 ·
I used Hedman in a '81 Camaro w/455. Fit great, but there's a brace that gets in the way on these cars that needs removed. IIRC your 1st gen F-body does not have that brace. Had M/T headers on a '68 LeMans w/428 that fit like hell, but ran good.

Use 4-tube headers, not 3-tube, regardless of the brand. Do what it takes to install whatever you get correctly- even if that means lifting the engine or whatever. You might find using new motor mounts gives some extra clearance depending on how old yours are.
 
#6 ·
If your manifolds are quite "heavy", you might just have the "good ones". That is, the "long branch" exhaust manifolds that fit 1st gen Firebirds. The plain-jane "log" manifolds aren't heavy at all. Do the manifolds "sweep" towards the rear and then straight down, with a bend that points the exit to the rear? All in all, about 14" long? If so, very few headers are "better" for power, and none will out-live them. If they're the "log" type (a straight "tube" with the ports exiting into it, and a small flange where the "down pipe" or "head pipe" attaches), I would recommend the Hookers. Mad Dog also makes very nice headers for the Pontiac and they fit quite well.

NOTE: If you're not sure about the manifolds being "log" or "long branch", PM me a pic or post a pic, and we can identify them for you. If you DO have the long-branch, don't spend a dime on headers...

I would disagree that Pontiacs are more difficult than "most" to install headers. Having worked in performance-oriented repair shops in the '70s, I put headers on hundreds (literally) of cars. There are two bolts that are difficult on the Pontiac. Those are the fourth one "back" on each side. A short open-end wrench, reaching in from the bottom, is the best way to get those, but the rest can be accessed easily by either a box-end wrench or (even better) a long extension and "wobbly" (swivel) socket from UNDER the car. You should put headers on a '68 Mustang with a 428 CJ in it... :)- or a '69 Road Runner w/Hemi... LOTS of "fun"...!

FWIW

Jim
 
#7 ·
Quick question Jim and I know that you would know. Would the "long branch" manifolds be available on a 68 350 Firebird? Even if it was the H.O. I've seen them on the 400's and had a set off of a 68 400 Comanche engine if I'm right. But never have seen them on a 350. If they where available, was it a rare option?

Ray
 
#8 ·
Ray,

Can't say FOR CERTAIN. I've seen a couple "HO" cars that had them. Whether or not they were original, I can't say. Seems logical they would, though.

I know one of the dumbest things I did when a "kid" was rip the long-branches off the '69 400 car and put cheap headers on it... Who knew...?

Jim
 
#9 ·
Jim...when it comes to doing dumb stuff to cars and especially my 67 Firebird when I was young, well, when I think back, it's scary some of the things that I thought were cool at the time I now know I should have been whipped for. Like throwing away my walnut steering wheel and shifter knob because I needed a small steering wheel and a T handle. Tossing my factory 5 spokes in favor of chrome slotted, (I couldn't afford the aluminum slotted) and my favorite, buying a Firebird with a bad engine because I liked the long scoops on the hood, took the hood off, went to the local gravel pit with an 8mm camera, stole some blasting caps and dynamite and blew the car up...perfect interior, straight car...I just wanted the hood.

Ray
 
#11 ·
good luck fitting headers into your car! i really hope it does not have AC.

put the car on jackstands, as high as you can. use a cherry picker and lift the engine about 16", you may need to lift more.

after you bleed, sweat and cuss, ALOT while getting the headers into position. ( beer & medicinal herbs helps this greatly if its your thing)

remember 1 thing.on the siameased exhaust port, the rear bolt must be put in before you slide the header into place.

now that your cussing again, please remind yourself that theres a gasket that goes there as well....BEFORE YOU PUT THE REST OF THE BOLTS IN..

hint. remove oil filter adapter, starter, trans lines, and in some cases shifter linkage. and use 3/8 head header bolts.(gives you more room)

i find it easier to tighten all the bolts while the car is still in the air from the bottom, besides the center rear bolt, i have a 3/8 wrench i cut down to fit this tight place.
 
#12 ·
A/C never seemed to get in the way from under the car. That's where the majority of the "work" is.

ARP also makes header bolts with a 5/16" hex head. Makes the wrench even easier...

Good point on the slot/hole arrangement. Like Pop always said: "When all else fails, follow instructions." This info is contained in the printed install instructions from Hooker.

Jim
 
#13 ·
A/C never seemed to get in the way from under the car. That's where the majority of the "work" is.


Jim
oops! i was thinking on a different application..

a 77 firebird, with a early block, and the engine mound adapters, with AC and a 4 speed is a PITA!

with hooker super comps for edel heads.

had many many issues, i had to redirect 3 tubes
1 on the pass side to clear the AC box on the firewall,
and 2 on the drive to clear bell crank and rear lower control arm mount
 
#14 ·
For me, most of the times that I've installed headers, getting the old manifolds off was a bigger PITA than installing the Headers. I can think of a number of cars that getting Headers into the engine bay is a chore beyond belief. Most Fords with shock towers. I remember a 67 Fury that it took three men, loosening all motor mounts, dropping the starter and a mess of other things besides holding your tongue in the right position to just get the passenger side Header to even go into place, let alone putting any bolts or gaskets in.

The Pontiacs are not the toughest, but, that being said...I don't understand why people wouldn't use Header bolt locks when they install headers...Those bolts are going to loosen up after you get the Header's bolted in...Use locks and you will save time...and money, because you won't be replacing Header Gaskets nearly as often.

Ray
 
#22 ·
Hotrod confused me a little, so are you saying the hedmans i am going to order will not be that bad to install onto my 68. you scared me about lifting the motor etc. i installed the stock log manifolds on the motor by myself and the only thing i really had to move was the starter.
 
#26 ·
The purpose of installing headers is to isolate the exhaust pulses fom each other, aiding the sound wave in both intake "filling" and scavenging of exhaust gasses. A "3-tube" header cannot achieve isolation, as two exhaust ports are "talking to each other" on each side. If the heat crossover is not blocked or "filled", you then have FOUR cylinders "cross-talking".

Again, headers should NOT be bought based on "ease of installation". Easy ones are seldom good ones...

Jim
 
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