C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Header Recomendations1981 With 700R4 mod

Thread Tools
 
Search this Thread
 
Old Feb 25, 2002 | 11:02 PM
  #1  
VETJET's Avatar
VETJET
Thread Starter
Instructor
 
Joined: Jan 2000
Posts: 134
Likes: 0
From: Bryant Ar
Default Header Recomendations1981 With 700R4 mod

Does anyone have experience installing headers on a 1981 with a 700R4 transmission swap? Also what other mods do I need to do if I run dual exhaust out the back and eliminate the catalytic converter. What brand of header worked the best?
Reply
Old Feb 26, 2002 | 12:08 AM
  #2  
MIKER's Avatar
MIKER
Melting Slicks
10 Year Member
 
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
Default Re: Header Recomendations1981 With 700R4 mod (VETJET)

I am using Headman headers on my car. The exhaust pipes were bent in a manner that allowed clearance of the transmission pan. I'm not sure if any one brand of header would provide more or less clearance than another.
My cross-member was notched by the installer to provide room for the dual exhaust.
Reply
Old Feb 26, 2002 | 12:47 AM
  #3  
Double Aught's Avatar
Double Aught
Race Director
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2000
Posts: 12,975
Likes: 22
Default Re: Header Recomendations1981 With 700R4 mod (VETJET)

Heddman here too. It is a tight fit, but really not a problem. I have the BTO crossmember and have to run a smog-legal exhaust. It y's after the pan. Ed Hanson Muffler Shop did a fantastic job.
Reply
Old Feb 26, 2002 | 03:00 PM
  #4  
Lt1er's Avatar
Lt1er
Drifting
 
Joined: Dec 1999
Posts: 1,462
Likes: 1
From: Reno nevada
Default Re: Header Recomendations1981 With 700R4 mod (VETJET)

If your 81 has dual exhaust holes through the crossmember they are actually to narrow and the pipes end up right next to the tranny. So an easy mod is just like Miker's picture where you cut out a half circle and weld in a plate straight back from your header collectors. That way the muffler shop will have an easy job with very few bends.
Reply
Old Feb 26, 2002 | 03:11 PM
  #5  
AD2VET's Avatar
AD2VET
Melting Slicks
15 Year Member
 
Joined: Aug 2000
Posts: 2,964
Likes: 0
From: Huntsville AL
CI 2-3-4-5-6-7-8-9-10 Vet
St. Jude Donor '09-'10
Default Re: Header Recomendations1981 With 700R4 mod (VETJET)

I put Hedman Headers on my '82 with true dual exhausts. I had the muffler shop custom bend the exhaust and routed them both under the passenger side. The driver's side exhaust crosses over behind the transmission pan to prevent any interference. Everything works well. Hope this helps.
Reply
Old Feb 26, 2002 | 03:11 PM
  #6  
Red73's Avatar
Red73
Melting Slicks
Supporting Lifetime Gold
20 Year Member
 
Joined: Feb 2000
Posts: 3,050
Likes: 9
From: Fairport NY
Default Re: Header Recomendations1981 With 700R4 mod (VETJET)

I would go with the cross member from BTO. With their cross member you could run any exhaust configuration that you would like. Go to my pictures below and look at the last set of pictures to see what BTOs cross member looks like installed on my car. Rod
Reply
Old Feb 27, 2002 | 11:05 PM
  #7  
VETJET's Avatar
VETJET
Thread Starter
Instructor
 
Joined: Jan 2000
Posts: 134
Likes: 0
From: Bryant Ar
Default Re: Header Recomendations1981 With 700R4 mod (Red73)

I installed the BTO crossmember when I installed the 700R4 tranny and it worked well with the exception of not wanting to modify my factory exhaust at the time. The factory exhaust had to be cut and modified to fit. I got into an arguement with the guy at BTO because nothing was mentioned about this when I buoght the crossmember and he replied that it was very rare for the car to still have its factory exhaust. I guess it it if you are installing the BTO crossmember.

So it sounds like the Hedman headers are bolting up without much trouble.

Are there any special modifications that need to be done to remove the catalytic converter and the diverter valve on the right hand manifold or anyother issues that need to be addressed when I remove the factory exhaust?


[Modified by VETJET, 9:07 PM 2/27/2002]
Reply
Old Feb 28, 2002 | 12:17 AM
  #8  
Prufrock17's Avatar
Prufrock17
Advanced
 
Joined: Feb 2002
Posts: 75
Likes: 0
From: Santa Clarita CA
Default Re: Header Recomendations1981 With 700R4 mod (VETJET)

I went with Doug Thorley headers on my 78. Fit nicely and noticed big gains.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Feb 28, 2002 | 12:47 PM
  #9  
Red73's Avatar
Red73
Melting Slicks
Supporting Lifetime Gold
20 Year Member
 
Joined: Feb 2000
Posts: 3,050
Likes: 9
From: Fairport NY
Default Re: Header Recomendations1981 With 700R4 mod (VETJET)

VETJET, I would guess that you got an early design of their crossmember. I just received and installed my BTO crossmember and you could run any exhaust configuration with this crossmember. Look at my picture link below and look at the last4 pictures. Rod
Reply

Get notified of new replies

To Header Recomendations1981 With 700R4 mod





All times are GMT -4. The time now is 01:11 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