Your 1 7/8 headers may be overkill
Definitely not worth worrying over too much for NA based on Richard Holener's dyno results in
Moral seems to be we should pay attention to the full exhaust (collectors & Y pipe, X pipe, true dual etc)
edit also remember t
he was running a 3" collector so it be advisable to run a 3" all the back.
First off, look at the different in the collectors between the two headers. We all know header collector design does play a role in this. the 1 3/4 headers have a better design collector where its longer and more gradual into the merge. Also, the supercharged 383 MADE MORE POWER with less boost. Bring the boost back to where it was.....well, I think we all know what will happen.
My opinion on this..... a 5.3, 5.7 and even most 6 liter engines won't need/benefit from 1 7/8.... but if you plan on more power, bigger engine or boost/nitrous later on, maybe just do the bigger headers from the onset so You arent spending money twice and/or regretting you didnt go bigger in the beginning. A 6.2 thats pretty stout with big heads and especially big exhaust ports will likely benefit....and over 400cu. in. making big power will benefit.
Sometimes I feel like his "tests" are quite like comparing apples to oranges in alot of ways and the average uninformed tinkerer will not know any better that details are being left out....that really matter.
First off, look at the different in the collectors between the two headers. We all know header collector design does play a role in this. the 1 3/4 headers have a better design collector where its longer and more gradual into the merge. Also, the supercharged 383 MADE MORE POWER with less boost. Bring the boost back to where it was.....well, I think we all know what will happen.
My opinion on this..... a 5.3, 5.7 and even most 6 liter engines won't need/benefit from 1 7/8....
Sometimes I feel like his "tests" are quite like comparing apples to oranges in alot of ways and the average uninformed tinkerer will not know any better that details are being left out....that really matter.
my setup is pretty simple but I still feel lost about headers for it lol.
4th gen Camaro: cam only LQ9 with a 233/243 -114+5 and the stock ls6 intake but it's still got a nice 7500rpm rev limit and So it could also use a better intake. Behind that a 4k stall 4L60e with 4:10 gears and 26" tires.
For exhaust I've got the eBay version (wonky tips) of the speed-e 3" duals that go out the back on the car and my old pace setter coated 1-3/4" headers from like 2004 are still kicking it
I would like to see a common and imperfect (has to fit on an actual car) exhaust like mine on holders dyno tried with a few different headers to see what works best. There is a nice x-pipe in my exhaust but the driver's side piping is much longer even before the x than the passenger side and it's even longer after that. The shorter passenger piping gets it's tips on that side dirty much faster after some driving so obviously there is a difference in flow on either side.
Thoughts?
Off topic.....I've got a procharged setup but shooting for low 600s. Do you have stock internals? (rods in particular). My tuner told me I'll be fine as long as I keep the rpms under 7000 and horsepower under 650 and torque under 600.
edit: Sorry, I just saw in your signature that you have a forged ls3 and probably all the upgraded goodies inside. lol
Last edited by 2001ws6ft; Jan 27, 2022 at 12:20 AM.
The Best V8 Stories One Small Block at Time
Off topic.....I've got a procharged setup but shooting for low 600s. Do you have stock internals? (rods in particular). My tuner told me I'll be fine as long as I keep the rpms under 7000 and horsepower under 650 and torque under 600.
edit: Sorry, I just saw in your signature that you have a forged ls3 and probably all the upgraded goodies inside. lol
How would you know there was no loss with the 1 7/8" headers unless they directly replaced some 1 3/4" headers? You didn't mention any previous headers
How would you know there was no loss with the 1 7/8" headers unless they directly replaced some 1 3/4" headers? You didn't mention any previous headers
These tests were done more than a decade ago and are on here some place. I don't remember what brand was what or any of the details other than this used to be an argument when 1 7/8 headers first became readily available for fbodies. The common consensus was that they were way too big unless it was some high compression drag race only stroker. Then people started testing them on stock engines and proved people wrong. Now, I do not believe (within logical reason of course) that you can have too big of a header on an engine. But that's personal opinion and no proof or experience to back it up so take it for what it is.

There was lots of controversy and the 1 7/8's generally came out as better overall based on what was posted. I posted a search and links to some of those threads earlier in this thread.
We all know different dyno, different day different set up means we can't say absolutely without testing.
I like Richard Holdener and his video's but there's nothing new about 1 7/8 headers in his video that Texas Speed, Lingenfelter and many others haven't shared with their testing many years ago.
Couple years ago, considered putting Lingenfelter's little GT2-3 cam (207/220 .571/.578 118.5) in my nearly stock 02 Z28. Talked in detail with LPE about best headers to purchase 1 3/4 vs 1 7/8 for that cam for best performance. Based on LPE's dyno results answer was a quality set of 1 7/8 headers.
RH provides as honest and accurate information as his budget allows and I'm grateful for it. However, one still needs to do the appropriate research for their project and not take YouTube video as gospel or at face value.
I think his conclusion is probably valid. Smaller tubes on the street and larger tubes for track. Your butt dyno probably won't know the difference though.
Last edited by wannafbody; Jan 29, 2022 at 12:49 PM.
There was lots of controversy and the 1 7/8's generally came out as better overall based on what was posted. I posted a search and links to some of those threads earlier in this thread.
We all know different dyno, different day different set up means we can't say absolutely without testing
Below is a link to the thread mentioned in quote.
https://ls1tech.com/forums/generatio...o-results.html











