 
Main Menu
|
|
Nevada Classics
|
|
Advertise at CC
|
| S |
M |
T |
W |
T |
F |
S |
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
| 8 |
9 |
10 |
11 |
12 |
13 |
14 |
| 15 |
16 |
17 |
18 |
19 |
20 |
21 |
| 22 |
23 |
24 |
25 |
26 |
27 |
28 |
| 29 |
30 |
31 |
|
|
|
|
|
|
CC Advertisers
|
|
 5Likes
09-08-2022, 07:13 AM
|
 |
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
Upgrade Headers
Hi All,
Currently running an era correct 289, looking to get into a 351W stroked out to a 427. My concerns are the headers that I have today may not be a match for my next generation build. I also looked at building a 302 stroked to a 347 and still feel the headers may be to small. Any suggestions on finding replacement headers? I also have a picture of the header size as an example.
|
09-08-2022, 08:13 PM
|
|
CC Member
|
|
|
Join Date: Feb 2021
Posts: 229
|
|
Not Ranked
wow, those flanges look thin. I saw somewhere in a past thread that there is a company that you can mock up your headers with a pvc kit and send it back and they make your header up.
https://www.gpheaders.com/products/custom-headers/ |
09-09-2022, 03:37 AM
|
|
CC Member
|
|
|
Join Date: Feb 2018
Cobra Make, Engine:
Posts: 347
|
|
Not Ranked
Since you are planning to change displacement,
This handy calculator can provide a starting point
for best header tube diameter and length considerations.
Primary Header Tube Length and Diameter Calculator |
09-09-2022, 03:39 AM
|
|
CC Member
|
|
|
Join Date: Feb 2018
Cobra Make, Engine:
Posts: 347
|
|
Not Ranked
And yes, those flanges look pretty thin.
Last edited by Unique427; 09-09-2022 at 03:46 AM..
|
09-09-2022, 06:43 AM
|
 |
Senior Club Cobra Member
|
|
|
Join Date: May 2007
Location: Longview,
Tx
Cobra Make, Engine: Classic Roadster, 408 LSX
Posts: 263
|
|
Not Ranked
Also remember if you go to a 351 block, the exhaust ports are a little higher and a little wider. Might or might not matter.
__________________
I've spent most of my money on cars and women. The rest I wasted.
|
09-09-2022, 06:56 AM
|
|
CC Member
|
|
|
Join Date: Aug 2000
Location: Pinellas Park,
FL
Cobra Make, Engine: built the molds and body composite construction
Posts: 316
|
|
Not Ranked
One thing to consider is that the firing order on the old 289 is different, meaning the pairing of cylinders on the left side of the engine is different for the new firing order which the 351 has making the headers different. With the 347 this same thing applies, the new firing order, if used in the 347 requires different header parings. This does not mean you can not use the old style headers with the new firing order, but it will not make as much HP and does change the sound slightly of the exhaust.
Bill K
|
09-09-2022, 06:58 AM
|
|
CC Member
|
|
|
Join Date: Aug 2000
Location: Pinellas Park,
FL
Cobra Make, Engine: built the molds and body composite construction
Posts: 316
|
|
Not Ranked
If you are running all four into one collector it doesn't matter.
Bill K
|
09-09-2022, 08:23 PM
|
|
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
Thanks!
I was thinking of going with 500 HP 347 Ford Small Block Stroker from PM.
Wanted to make sure the headers would not be an issue? I attached the link to the actual crate motor.
https://www.prestigemoto.com/custom-...347-hr-c3.html |
09-10-2022, 11:04 AM
|
 |
CC Member
|
|
|
Join Date: May 2015
Location: Lake Geneva,
WI
Cobra Make, Engine: Classic Roadsters 427, 5.0
Posts: 365
|
|
Not Ranked
Those are thin flanges! What year was your CRII made? Mine is a 1990 kit (CRI) and not nearly as thin as yours. If you do go to a 351 block, it will lift the header exit mount and the opening at the bottom of the body will not align by about 3/4".
|
09-10-2022, 11:25 AM
|
 |
CC Member
|
|
|
Join Date: Nov 2009
Location: Edmond,
Ok
Cobra Make, Engine: Classic Roadsters
Posts: 627
|
|
Not Ranked
The view of the flange is blocked by the valve cover. They are 5/16” thick flange, Classic Roadsters header.
They are to small for what you want.
__________________
 Chaney Shores Studio
Last edited by sunman; 09-11-2022 at 08:40 AM..
|
09-10-2022, 07:53 PM
|
|
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
So basically I’m better of with staying with a 289 or 302?
|
09-10-2022, 10:50 PM
|
|
CC Member
|
|
|
Join Date: Aug 2021
Location: Beaumont,
TX
Cobra Make, Engine: Classic Roadsters, Ford coyote Gen1
Posts: 72
|
|
Not Ranked
 A 331 and 347 stroker use the same block as the 302. Your choice of heads can vary between Windsor, Cleveland, or after market combination and cc. Your choice which direction you go, but improving the exhaust headers will benefit you in squeezing all you can from your chosen platform.
I had mine custom made to benefit my motor.
__________________
Mark
Last edited by markantioch; 09-10-2022 at 10:54 PM..
Reason: picture
|
09-11-2022, 02:46 AM
|
|
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
Who did the headers for you?
|
09-11-2022, 03:35 AM
|
|
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
Who did the headers for you?
I still am trying to figure out if I buy a 302 crate motor will the headers on the car fit? I was going to go with a 347 striker but it sounds like the headers will not fit so I’m down sizing to a 302.
https://www.westcoastengines.com/302-engine |
09-11-2022, 04:54 AM
|
|
CC Member
|
|
|
Join Date: Aug 2000
Location: Pinellas Park,
FL
Cobra Make, Engine: built the molds and body composite construction
Posts: 316
|
|
Not Ranked
In my opinion go with the 347, the headers should fit [b]Period[/B unless the heads are something really weird, a FORD crate 347 with Ford 304 heads should be a bolt in. You get into trouble when you use the 351W block because of the increased deck height.]
Bill K
|
09-11-2022, 05:54 AM
|
|
CC Member
|
|
|
Join Date: Aug 2021
Location: Beaumont,
TX
Cobra Make, Engine: Classic Roadsters, Ford coyote Gen1
Posts: 72
|
|
Not Ranked
They were fabricated in Ohio, and the drivers side modified in Houston cus it was a lil to long. Material cost I don't remember, but the labor cost to build them was $400 back in 2015.
__________________
Mark
|
09-11-2022, 07:14 AM
|
|
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
Thanks Bill K!
Really want the 347 FORD SMALL BLOCK STROKER CRATE ENGINE: F347-HR-C3. I hope the existing headers don’t restrict the HP to much.
https://www.prestigemoto.com/custom-...347-hr-c3.html |
09-11-2022, 07:18 AM
|
|
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
Thanks everyone for your advice! All good stuff!
|
09-11-2022, 08:08 AM
|
|
CC Member
|
|
|
Join Date: Nov 2009
Location: Edmond,
Ok
Cobra Make, Engine: Classic Roadsters
Posts: 627
|
|
Not Ranked
This is what you have.
The flange is 5/16”. The tubes are 1 5/8”.
The outside of the tubes are not welded and you can weld outside and enlarge the tube inside.
That’s good for the 302 but small for 500 HP tho.
If you go 347 maybe send them to someone to be duplicated in 1 3/4” tubes.
__________________
Chaney Shores Studio
Last edited by sunman; 09-11-2022 at 09:06 AM..
|
09-11-2022, 01:26 PM
|
|
CC Member
|
|
|
Join Date: Jun 2022
Cobra Make, Engine:
Posts: 106
|
|
Not Ranked
Thanks!
Now you got me thinking, maybe I send my headers to a fab shop for fit with 1 3/4 across the board. Anyone know a good custom header shop?
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -7. The time now is 04:39 AM.
Links monetized by VigLink
|
Linear Mode
