Header size
Header size Good afternoon,
I have an ls3 in my g body with an ls3. The previous combo in the car was an L76 with the same cam and heads. That engine made 500 whp, so I know the new ls3 should be more. As it sits, it has tsp ported heads, a tsp ls3 stage 3 cam (231/246 .640"/615), Herman 1 3/4 mid length header, 10.7:1, run by a Holley terminator x max. It is backed by a TREMEC magnum and ford 9”. My question is, I just got a deal on a pair of Holley 1 7/8 long tubes but am unsure if I should run them or sell/trade for a set of 1 3/4 headers. Looking for opinions. Thank you
I have an ls3 in my g body with an ls3. The previous combo in the car was an L76 with the same cam and heads. That engine made 500 whp, so I know the new ls3 should be more. As it sits, it has tsp ported heads, a tsp ls3 stage 3 cam (231/246 .640"/615), Herman 1 3/4 mid length header, 10.7:1, run by a Holley terminator x max. It is backed by a TREMEC magnum and ford 9”. My question is, I just got a deal on a pair of Holley 1 7/8 long tubes but am unsure if I should run them or sell/trade for a set of 1 3/4 headers. Looking for opinions. Thank you
This subject has been beat on the head many times.. It is in my (non professional) opinion that you should run the 1 7/8 with that combo.. Especially since the long tubes are just that.. longer. You will benefit from the longer primaries. Benefitting from the larger diameter is up for debate but I think it'll be a solid upgrade for you.
TECH Senior Member
Joined: Jun 2016
Posts: 22,289
Likes: 3,615
From: Central Cal.
TECH Senior Member
Joined: Jun 2016
Posts: 22,289
Likes: 3,615
From: Central Cal.
It has been found that while 1-3/4" can choke a higher HP engine, the reverse isn't true for the larger header losing low end torque (old thinking....) . So it's a win-win.
That all being said above many times it what fits the car best and has the least amount of hassles for you as far as plug changes, heat soaking starter solenoid, hitting steering column etc. If you know the 1 7/8 fit fine then great but if they come with a bunch of headaches it is not worth the 10-20 hp to have a bunch of other problems. I come from Chevelleworld and many times spending on quality along with a good fitting header (less hassles and hammer dingings) is way better than the 10 hp lost.
Trending Topics
In my opinion 1-7/8 is ideal for an LS3 with the added cubes and better head flow of the rectangle heads. Years ago on here there was a lot of debate over 3/4 vs 7/8 on a 346 with cathedral heads, and generally the data showed even an LS1 benefitted with the larger primaries and gave up almost nothing down low. So on the bigger, better flowing motor, it seems a no brainer. I run 7/8 on my stock cam LS3- probably making ~400whp, as most SS Sedan guys do.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
