TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC 6 Cylinder Engine Repair and Modifications
  New Posts New Posts RSS Feed - Headers for a 258 in a Concord
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

Headers for a 258 in a Concord

 Post Reply Post Reply Page  <123>
Author
Message
Ollie View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Sep/17/2012
Location: Brandon, MS
Status: Offline
Points: 2517
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ollie Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2019 at 11:08am
Originally posted by Mr_AMC Mr_AMC wrote:

http://catalog.remflex.com/AMC_Jeep_Header_Exhaust_Manifold_Gasket_p/10-003.htm

That's the gasket.

I will say one thing in defense of the headers.......my 232 sounds awesome with them and some turbo mufflers. Everyone thinks its a small V-8.

Having AMC Fun,
Ollie
1966 American Convertible -- "The Rambler"
1974 Postal Jeep -- "Rapid Delivery"
1969 Rambler 220 post car--"Road Warrior"
Back to Top
matty 401 View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jul/06/2007
Location: Iowa
Status: Offline
Points: 1423
Post Options Post Options   Thanks (0) Thanks(0)   Quote matty 401 Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2019 at 4:43pm
i turn 5000 with my 258 when i had my 77 AMX  258 4 speed dump the clutch about 32-3800  not sure where my 79 concord winds to lol
72 matador 401 the beast
79 concord 2 door
72 matador 304 grasshopper
68 Rogue 360
93 Cherokee 2wd 4.0 5 speed
Back to Top
Pdok View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Apr/03/2011
Location: Alabama
Status: Offline
Points: 920
Post Options Post Options   Thanks (0) Thanks(0)   Quote Pdok Quote  Post ReplyReply Direct Link To This Post Posted: Nov/05/2019 at 5:01pm
x10 on the RemFlex gaskets... I can't believe I never knew about them, but they are better than anything else I've ever used.  The Clifford gaskets went in the trash.  I've had both 4.2 and 4.0 headers from clifford, no problems with either one bolting right up.  BUT, they are plain steel, so plan ahead to have them coated somehow.

And, header w/single flowmaster pro series muffler sounds awesome...
76 Grem X 258/904,4.0 head/MPFI, Comp X250H cam, Hughes springs, Clifford header, serpentine swap.
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 17211
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Nov/06/2019 at 6:16am
How much does a 4.0L head add? It depends on the build. The head and mandatory header alone won't add more than 5-10 hp depending on the rest of the exhaust system, and that hp will be mostly near the top end due to the added flow. You will get a little torque increase at the low end due to the better shaped ports. All these articles about bolting on 20-25 hp and such by swapping the head are misleading. They have to be swapping the EFI with the head for that kind of an increase. The head will flow a LOT better than any of the 258 heads. Even though the ports are smaller, they are much better shaped so flow much better. The ports are raised to have a better arc into the cylinder, for one thing. The 258 big ports have a near 90 degree turn into the cylinder, and have lots of turbulence in them - intake and exhaust. You can get 20-25 hp with the head -- and a better cam, intake, and carb that will make use of the added flow. Or the EFI, assuming you're replacing a stock BBD 2V and stock ignition system (that may not be running well).

You can get the parts cheap enough for the EFI from a junkyard now, so it's not an expensive (or hard) swap. But if you prefer a carb you're on the right track. The aluminum factory 2V intake with a MC2100 or 2150 is an upgrade over the stock iron intake and WCD or BBD carbs. An Offy DP 4V intake and a 390-450 cfm 4V carb might be better, depends on what you're doing. A Weber 32/36 is great for economy and a little more power since it's a progressive carb (runs on the 32, the 36 barrel opens as needed, like a 4V). Depends on what you want from the car.

I only recommend the 4.0L head due to the high cost of Clifford 258 headers and the fact that you can run the factory header, and there are many aftermarket 4.0L header options. That and if you have a 258 head that needs rebuilding anyway, or plan on building a performance six. You get a much better aluminum or steel valve cover (later model 4.0L is steel) to boot. Add the cost of an aftermarket VC and header up...
Frank Swygert
Back to Top
Mr_AMC View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Sep/27/2010
Location: Charleston, SC
Status: Offline
Points: 115
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mr_AMC Quote  Post ReplyReply Direct Link To This Post Posted: Nov/07/2019 at 12:18pm
The sound of the headers and dual exhaust is the MAIN reason I want them..
Glad to hear that you think they sound awesome..

Thanks
Back to Top
g-man View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jul/05/2007
Location: Cal Coast
Status: Offline
Points: 586
Post Options Post Options   Thanks (0) Thanks(0)   Quote g-man Quote  Post ReplyReply Direct Link To This Post Posted: Nov/07/2019 at 2:43pm
Originally posted by Mr_AMC Mr_AMC wrote:

The sound of the headers and dual exhaust is the MAIN reason I want them...

I am with you on that.
I have a '77 Gremlin (exact same engine bay as a Hornet/Gremlin) with a '74 258 w/ .030 overbore, mild cam, slight CR increase, mild head work, with Clifford headers that we built back in the early '90's. The car had dual 2-chamber Flowmasters with 2 1/4" non-mandrel bent tubing. The exhaust went up & over the rear axle, and then ended right there shooting out at a 45 degree angle.
I had people arguing with me that I had a V-8 under the hood...I would literally have to open the hood to get them to shut up!
On the other hand, the damn things hit everything taller than an ant on the road, with the car being stock height. Definitely get shorties no matter what you do! 
And then nowadays, I have heard from many sources, including here (just ask Ollie), that Clifford's quality has gone way down. It is unfortunate that you're stuck with the 258 head. I can tell you that when I freshen this Gremlin and put it back on the road, we will only be using the 4.0 head, and won't have to have header problems anymore, in addition to the better flowing head.
Maybe you can find a used Clifford header, and just use the flange, and find a used 4.0 shorty header, and cut off the flange of the 4.0 header and put them together somehow?
Good luck with whatever you end up doing. 
Keep us posted,

g-man
AMC only daily driver
Back to Top
g-man View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jul/05/2007
Location: Cal Coast
Status: Offline
Points: 586
Post Options Post Options   Thanks (0) Thanks(0)   Quote g-man Quote  Post ReplyReply Direct Link To This Post Posted: Nov/08/2019 at 3:52pm
Originally posted by g-man g-man wrote:

The car had dual 2-chamber Flowmasters with 2 1/4" non-mandrel bent tubing. The exhaust went up & over the rear axle, and then ended right there shooting out at a 45 degree angle.

Forgot to mention that the exhaust has an "H" pipe.
It sounds redundant, but definitely install an H-pipe on your system.
The only thing I would change is: when I put it back on the road, I will change the H-pipe to an "X" pipe.
A lot of people will tell you that it's a waste of time...but I tell you that it is definitely worth the effort!

g-man  
AMC only daily driver
Back to Top
Mr_AMC View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Sep/27/2010
Location: Charleston, SC
Status: Offline
Points: 115
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mr_AMC Quote  Post ReplyReply Direct Link To This Post Posted: Nov/14/2019 at 2:42pm
wondering   Does the H or X pipe setup make a difference in the sound?? or the performance??
Back to Top
g-man View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jul/05/2007
Location: Cal Coast
Status: Offline
Points: 586
Post Options Post Options   Thanks (0) Thanks(0)   Quote g-man Quote  Post ReplyReply Direct Link To This Post Posted: Nov/14/2019 at 2:54pm
Originally posted by Mr_AMC Mr_AMC wrote:

wondering   Does the H or X pipe setup make a difference in the sound?? or the performance??

Both. The H pipe equalizes the exhaust pulses between both sides of the separate exhaust pipes. It will create an audible difference. A bit of a more melodious sound.
The X pipe simply does it more efficiently, as it does not create turbulence in the exhaust flow. Exhaust has a real tough time making 90 degree turns.

g-man
AMC only daily driver
Back to Top
Ollie View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Sep/17/2012
Location: Brandon, MS
Status: Offline
Points: 2517
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ollie Quote  Post ReplyReply Direct Link To This Post Posted: Nov/14/2019 at 3:30pm
I must say my 232 with the Clifford headers sounds awesome and everyone thinks its a V8.

 I have no H or X pipe because its a convertible. There is an extra plate, across the frame,  just in back of the transmission. It gave my muffler man h_ll, but he did it. We used some cheapo turbo mufflers.

The 'vert sounds way better than "The 69", but going down the road it is more better to listen to some rock and roll on the stereo, something that cannot be done in the 'vert. i.e. because of all the top wind noise and the sweet mellow sound of exhaust. I guess both conditions are winners....Wink

Having AMC Fun,
Ollie
1966 American Convertible -- "The Rambler"
1974 Postal Jeep -- "Rapid Delivery"
1969 Rambler 220 post car--"Road Warrior"
Back to Top
 Post Reply Post Reply Page  <123>
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.078 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or