1 3/4" Headers Verses 1 7/8" on a Healthy 408....Is There a Big Difference??

-
flyfish

flyfish

C8H18+N2O = :-D
Joined
Apr 16, 2007
Messages
2,501
Reaction score
1,229
Location
Indy
I've got some money burning a hole in my pocket, and I'm wondering if it would make any real difference swapping from my current 1 3/4" Headman Hustlers to the 1 7/8" Headman Hustlers. I think my engine is right on the boarder of "needing" 1 7/8" headers, but I'm not sure if I would gain much (if any) with the swap.

My car, incase you are not familiar:

67 Barracuda (about 3250# with me), 408 stroker, 13:1 compression on e85, ported Edelbrocks, 264/268 duration @ 0.05 with 0.621/0.632 lift solid flat tappet, Victor intake, 727 with 8" converter, 4.10 gear, 275/60/r15 Hooiser DR.

Current best 10.1x @ 130mph, but usually runs 10.3x in the summer heat.

I would just hate to spend the time and money on new headers if they don't to squat....or slow the car down.

Thoughts?
 
I was running 1 5/8" street type headers with extensions on my 408 & I changed to 1 7/8" race headers with long collectors. I saw a small change in ET & MPH to the good. I didn't get a chance to really wring out the 408, I'm in the process of building a 416 because I dropped a valve in the 408, I guess we will see if there is any improvement with the 416.
 
flyfish said:
I've got some money burning a hole in my pocket, and I'm wondering if it would make any real difference swapping from my current 1 3/4" Headman Hustlers to the 1 7/8" Headman Hustlers. I think my engine is right on the boarder of "needing" 1 7/8" headers, but I'm not sure if I would gain much (if any) with the swap.

My car, incase you are not familiar:

67 Barracuda (about 3250# with me), 408 stroker, 13:1 compression on e85, ported Edelbrocks, 264/268 duration @ 0.05 with 0.621/0.632 lift solid flat tappet, Victor intake, 727 with 8" converter, 4.10 gear, 275/60/r15 Hooiser DR.

Current best 10.1x @ 130mph, but usually runs 10.3x in the summer heat.

I would just hate to spend the time and money on new headers if they don't to squat....or slow the car down.

Thoughts?
Click to expand...


If you want to see it, get the engine on a dyno. I’d say you can test headers on a chassis dyno but swapping headers in the car is a genuine, over the top battle Royale PITA.

It’s probably easier to pull the engine and put it on the pump to test headers.

BTW, what’s the LSA on the cam? With only 4 degrees of split you SHOULD a make more power with the bigger headers.
 
yellow rose said:
If you want to see it, get the engine on a dyno. I’d say you can test headers on a chassis dyno but swapping headers in the car is a genuine, over the top battle Royale PITA.

It’s probably easier to pull the engine and put it on the pump to test headers.

BTW, what’s the LSA on the cam? With only 4 degrees of split you SHOULD a make more power with the bigger headers.
Click to expand...
108 LSA
 
YOu have a very built engine in the 400 cubic inch bracket(big block cubes). Bigger headers are your friend.
 
I will bet it makes a little more power, but the roi in time and dollars? I dont think i would do it,(unless you HAVE to have a 9.xx slip, lol).

To be honest, i ran a 2"header with 3 1/2 exhaust on my 406. (Headers were custom, came with the car). 6.2x eigths, through the mufflers. Less motor than you, but LOTS less weight.
 
Last edited:
years ago, I changed from 1 3/4 to 1 7/8, length was 35 ". my car (340) ran two tenths and two mph faster. a friend of mine tested 1 3/4 vs 1 7/8 on his 340, on a dyno, he found 30 hp. vs 1 3/4. just food for thought.
 
I know from 1 5/8 - 1 7/8 on my 408 was very noticeable, even with exhaust..
 
Since you already have basically a race type header I’m betting you see little to no gain. The exhaust ports on the Edelbrock heads are so screwed up shape wise you are pissing into the wind. I aim for port air speed rather than a flow number and although I always post flow numbers without tubes have tested and played around with different tubing sizes. Invest your money somewhere else.
 
Last edited:
Just make sure you retune it when make changes to the headers or exhaust for that matter.
 
I am keeping my 1 5/8 headers from my 360 and putting them on my 418.
Not sure what they are gonna cost me, but they fit nice...lol
 
i have no answer to your question, but would love to see a test.....i´m in the middle of installing the hedman 1 7/8" in my car....don´t know when i´ll be able to go to a track this year. Motor is also disassembled, crank thrust bearing damaged - waiting for a new crank. What kind of collector extensions do you run with your current headers?

Michael
 
B3422w5 said:
I am keeping my 1 5/8 headers from my 360 and putting them on my 418.
Not sure what they are gonna cost me, but they fit nice...lol
Click to expand...
Sometimes you have to live with what you got. My short exhaust system is fabricated/welded and positioned in such a way in unison with my 1-5/8" Dougs that, unless there were 1-7/8" headers out there that were identical, my bed is made.
 
12many said:
Sometimes you have to live with what you got. My short exhaust system is fabricated/welded and positioned in such a way in unison with my 1-5/8" Dougs that, unless there were 1-7/8" headers out there that were identical, my bed is made.
Click to expand...

yep
the headmans are the only way i would upgrade, and they require cutting, so....
 
The 1 7/8 headers on my 360 work real good, i thought they maybe to big, but that does not seem to be the case.
 
Seriously another 1/8 inch “PROBABLY “ isn’t going to give you much in the seat of the pants. I say probably as a disclaimer because there is no way everyone will agree with me. I’ve seen it too many times here.
Not to mention cost and frig factor
I say spend 3-400 bucks for a 150 shot of gas and go into the 9”s
Yes I already I’m going to get a lot of s..t
From saying this
 
Last edited:
I'll just tell you this. When running examples through pipemax, the trend is that the more efficient the engine (VE) the smaller the pipes needed, all other things being held the same.
The other thing to look at is where the power band is. The higher in the rpm range that the engine runs, the larger pipes it will prefer.
 
Brooks James said:
Seriously another 1/8 inch “PROBABLY “ isn’t going to give you much in the seat of the pants. I say probably as a disclaimer because there is no way everyone will agree with me. I’ve seen it too many times here.
Not to mention cost and frig factor
I say spend 3-400 bucks for a 150 shot of gas and go into the 9”s
Yes I already I’m going to get a lot of s..t
From saying this
Click to expand...


I’ve seen it way too many times in the dyno. A bigger header makes a difference IF the cam timing is correct for it. You have to let the header do what it’s designed to do, and certain cam timing events make the header almost a non factor.


Fix the cam timing and the bigger header wins every time. Just because someone on here puts a header on their car and it doesn’t run quicker or slows down means little to me. You ASSume they all can tune. Tune an engine. Tune a chassis. I know some guys that can’t run a timing light.
 
Mattax said:
I'll just tell you this. When running examples through pipemax, the trend is that the more efficient the engine (VE) the smaller the pipes needed, all other things being held the same.
The other thing to look at is where the power band is. The higher in the rpm range that the engine runs, the larger pipes it will prefer.
Click to expand...

There was a good thread on Speedtalk a while back:1 5/8” headers and 500hp? - Don Terrill’s Speed-Talk

This quote was interesting:
"Chris at C & S Performance "radically detuned" our best / fastest SBC442cid that made 816 HP @ 8200-8300 RPM
to around 670's to 680's HP with 1 5/8ths Headers + less Cam , i think less Comp Ratio , Carb CFM "

He later states its 640 HP
 
Hysteric said:
There was a good thread on Speedtalk a while back:1 5/8” headers and 500hp? - Don Terrill’s Speed-Talk

This quote was interesting:
"Chris at C & S Performance "radically detuned" our best / fastest SBC442cid that made 816 HP @ 8200-8300 RPM
to around 670's to 680's HP with 1 5/8ths Headers + less Cam , i think less Comp Ratio , Carb CFM "

He later states its 640 HP
Click to expand...
Custom 1 5/8 with 4" collectors, those ain't no dougs/tti headers.
 
I'd put as big a tube header on that thing as will fit. 2 1/4" if I could stuff it in.
 
All this header talk in many ways is directed at people who want to get every hundredth out of a car they can.... class racers, etc, etc.
Me, ... not so much. Whether my car runs 10.65 or 10.75 because of using one header or another, I could care less at this point. I am going to bracket and index race it, so every last tenth isnt needed.
I have to look at ease of installing, cost, and other factors first.
If i cared about going fast, i wouldnt be sticking tiny eddie heads on a 418 inch motor in the first place..lol. Or for that matter, even Trick flows, if i had them... too small as well
I will know if it runs as it should, that's good enough for me at this point.
 
B3422w5 said:
All this header talk in many ways is directed at people who want to get every hundredth out of a car they can.... class racers, etc, etc.
Me, ... not so much. Whether my car runs 10.65 or 10.75 because of using one header or another, I could care less at this point. I am going to bracket and index race it, so every last tenth isnt needed.
I have to look at ease of installing, cost, and other factors first.
If i cared about going fast, i wouldnt be sticking tiny eddie heads on a 418 inch motor in the first place..lol. Or for that matter, even Trick flows, if i had them... too small as well
I will know if it runs as it should, that's good enough for me at this point.
Click to expand...

Well, if you've got a "stout 408" WHAT exactly are your intentions if not to get all the power you can from a small block in the first place? lol So yeah, I agree with your cylinder head assessment 100% Can somebody say Trick Flow or Indy?
 
You must log in or register to reply here.
-

Back
Top