C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

LT1 header thread size

Thread Tools
 
Search this Thread
 
Old Mar 31, 2008 | 01:07 PM
  #1  
anesthes's Avatar
anesthes
Thread Starter
Safety Car
Supporting Lifetime
20 Year Member
All Eyes On Me
Photogenic
Photoriffic
 
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Default LT1 header thread size

What size threads are these on the AIR tubes? I bought so 2061 headers, and need to hook up the AIR tubes. It looks like a fine thread.

The '87 stuff won't fit/is different.

-- Joe
Reply
Old Mar 31, 2008 | 01:15 PM
  #2  
F1Fan's Avatar
F1Fan
Drifting
15 Year Member
 
Joined: Jun 2004
Posts: 1,477
Likes: 87
Default

My '95 uses an M21 thread for the air injection ports on the headers.
I was struggling to find a fix for this myself, but on another site, someone had suggested using an M21 oil drain plug for it. Or you can find a plug/disc/etc that can block the hole and then cut the old fittings off the air pipes and use those to hold it down.
Reply
Old Mar 31, 2008 | 01:29 PM
  #3  
anesthes's Avatar
anesthes
Thread Starter
Safety Car
Supporting Lifetime
20 Year Member
All Eyes On Me
Photogenic
Photoriffic
 
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Default

Originally Posted by F1Fan
My '95 uses an M21 thread for the air injection ports on the headers.
I was struggling to find a fix for this myself, but on another site, someone had suggested using an M21 oil drain plug for it. Or you can find a plug/disc/etc that can block the hole and then cut the old fittings off the air pipes and use those to hold it down.
M21 drain plug? Sounds good. I'll dill out the center and weld a 90* to it.

Thanks a bunch!

-- Joe
Reply
Old Mar 31, 2008 | 10:19 PM
  #4  
Eddie & the Cruisers's Avatar
Eddie & the Cruisers
Burning Brakes
 
Joined: Apr 2006
Posts: 765
Likes: 0
From: Houston Texas
Default

Originally Posted by F1Fan
My '95 uses an M21 thread for the air injection ports on the headers.
I was struggling to find a fix for this myself, but on another site, someone had suggested using an M21 oil drain plug for it. Or you can find a plug/disc/etc that can block the hole and then cut the old fittings off the air pipes and use those to hold it down.
The left and right are a different size on a '94 LT1 or is it the tube size that's different?
Reply
Old Apr 1, 2008 | 09:58 PM
  #5  
anesthes's Avatar
anesthes
Thread Starter
Safety Car
Supporting Lifetime
20 Year Member
All Eyes On Me
Photogenic
Photoriffic
 
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Default

It ended up being 22MM on both sides.

-- Joe
Reply
Old Apr 1, 2008 | 10:57 PM
  #6  
C4forlife's Avatar
C4forlife
Racer
15 Year Member
 
Joined: Sep 2005
Posts: 344
Likes: 0
From: Duncanville Texas
Default drain plug

I got mine at oreilly auto in the area where they have all the generic stuff like window cranks vacuum tubing etc. The application is a cummins diesel dodge.
Reply
Old Apr 2, 2008 | 06:56 AM
  #7  
anesthes's Avatar
anesthes
Thread Starter
Safety Car
Supporting Lifetime
20 Year Member
All Eyes On Me
Photogenic
Photoriffic
 
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Default

Originally Posted by C4forlife
I got mine at oreilly auto in the area where they have all the generic stuff like window cranks vacuum tubing etc. The application is a cummins diesel dodge.
Good to know! I searched through a bin of fittings for 10 minutes. They didn't end up charging me for them.

-- Joe
Reply

Get notified of new replies

To LT1 header thread size





All times are GMT -4. The time now is 08:22 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE