2” headers 408
Thread Starter
10 Second Club
Joined: Jan 2010
Posts: 2,317
Likes: 20
From: Hurley, VA
2” headers 408 My 408 has been built since 2014 and always had 1 7/8 headers. Would going to a 2” header pick up anything? The car made 571/522 with the air box lid removed ( had a intake restriction) I’m addressing that now with a pro stock 1313 but looking to get back into racing the car and trying to get all I can NA.
On The Tree
Joined: Feb 2023
Posts: 109
Likes: 59
Pretty loaded question. Assuming it's a max effort build because you said all I can get NA, I would think in some circumstances you could see some top end gains. Things like head flow, cam duration and the exhaust after the header will all play a big part.
TECH Resident
Joined: Oct 2014
Posts: 898
Likes: 71
There’s only one way to find out in drag racing… test it out. Years ago on here there was a guy with a built 383 ls1 that switched from 1 7/8” to 2” and saw some mild gains. I can’t remember who it was but I remember it wasn’t a radical build. I’ve seen it a few times.
I think it really depends on the build. How high are you turning it? Cam selection? Obviously the more rpm and cam and airflow you have the more air needs to come out. If you’re going all out N/A I’d say try it.
I think it really depends on the build. How high are you turning it? Cam selection? Obviously the more rpm and cam and airflow you have the more air needs to come out. If you’re going all out N/A I’d say try it.
Thread Starter
10 Second Club
Joined: Jan 2010
Posts: 2,317
Likes: 20
From: Hurley, VA
408 PRC247s, Vengeance ported Fast 102, 251/259 .624/.624. Compression is 11.5 static. It made 571/522 with the air box lid removed but it doesn’t seem to want much rpm above 6500. I’ve got a Prostock1313 set up to eliminate the intake restriction. Exhaust is a 3” y into a 4” merge with a cutout in the I pipe.
408 PRC247s, Vengeance ported Fast 102, 251/259 .624/.624. Compression is 11.5 static. It made 571/522 with the air box lid removed but it doesn’t seem to want much rpm above 6500. I’ve got a Prostock1313 set up to eliminate the intake restriction. Exhaust is a 3” y into a 4” merge with a cutout in the I pipe.
Trending Topics
Thread Starter
10 Second Club
Joined: Jan 2010
Posts: 2,317
Likes: 20
From: Hurley, VA
LS7 lifters, stock rockers with the bearing style trunions from 10 years ago, and 11/32 pushrods. I’ve considered going to a ported MSD but was afraid it’d move the power band to high for my valve train and still not pick up any ET.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
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 A short travel Johnson and an msd would do it some good. It'll gain you a couple hundred or so more rpm
12 Second Club
Joined: Dec 2017
Posts: 1,033
Likes: 221
From: San Antonio
If you want to rev it higher, then you need a short runner intake. The FAST has 3 different runner lengths available. Get the shorter runners, and it will rev past 7k. You should be able to take the intake apart and replace the runners yourself.
I don't know if that will improve your ET, but it will make your engine rev higher.
I don't know if that will improve your ET, but it will make your engine rev higher.
If you want to rev it higher, then you need a short runner intake. The FAST has 3 different runner lengths available. Get the shorter runners, and it will rev past 7k. You should be able to take the intake apart and replace the runners yourself.
I don't know if that will improve your ET, but it will make your engine rev higher.
I don't know if that will improve your ET, but it will make your engine rev higher.