Side Exhaust Dilemma
Thread Starter
6th Gear
Joined: Mar 2019
Posts: 6
Likes: 0
Side Exhaust Dilemma
Hi Everyone! Hopefully someone will be able to help or point me in the right direction. I have an '80 Vette with a ZZ4 crate motor from GM Performance. I really would like to make the move to side exhaust, but so far I'm running into dead ends application wise. The heads are the aluminum fast burn with angle plugs that come stock on the ZZ4. Doug's would be my header of choice, but all applications state "not for use with angle plug heads". Has anyone else dealt with this before? Is there something out there to make this happen?
Drifting
Joined: Feb 2007
Posts: 1,498
Likes: 206
From: Pearland Texas
St. Jude Donor '09
Hi Everyone! Hopefully someone will be able to help or point me in the right direction. I have an '80 Vette with a ZZ4 crate motor from GM Performance. I really would like to make the move to side exhaust, but so far I'm running into dead ends application wise. The heads are the aluminum fast burn with angle plugs that come stock on the ZZ4. Doug's would be my header of choice, but all applications state "not for use with angle plug heads". Has anyone else dealt with this before? Is there something out there to make this happen?
ZZ5 GM performance here with angled plugs too. I was told the same. No problem with hooker headers on my 74!!
Drifting
Joined: Feb 2007
Posts: 1,498
Likes: 206
From: Pearland Texas
St. Jude Donor '09
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
OP
ZZ4 did not come with fastburn heads.
ZZ4 chamber is a conventional shape and is same head as C4 L98 engine heads. ZZ4 has angle plugs and D port exhaust and conventional Intake port.
Casting number 10088113.
GM no longer markets ZZ4 heads.
------------------------------------------------------------------------------------------------------------------------------
ZZ5 (as in post #2 pics) came with fastburn heads which also have angle plugs & D port exhausts but the chamber is the newer fastburn style and has Vortec type intake port.
Casting number 12367712.
ZZ4 did not come with fastburn heads.
ZZ4 chamber is a conventional shape and is same head as C4 L98 engine heads. ZZ4 has angle plugs and D port exhaust and conventional Intake port.
Casting number 10088113.
GM no longer markets ZZ4 heads.
------------------------------------------------------------------------------------------------------------------------------
ZZ5 (as in post #2 pics) came with fastburn heads which also have angle plugs & D port exhausts but the chamber is the newer fastburn style and has Vortec type intake port.
Casting number 12367712.
Team Owner
Joined: Jul 2004
Posts: 40,404
Likes: 791
From: Redondo Beach, California
I have the 1969 factory side mount header system on my 68. The headers are Hedman's. I have a ZZ4 engine with the angle plugs. The catalog says they are not for angle plugs. However they fit just fine. The ZZ4 exhaust ports are D ports. The Hedman headers are rectangular ports. There's very little difference between D ports and rectangular ports. A little grinder action on the headers makes a good approximation of a D port. Edelbrock's intake manifold and head designer said don't worry.....the exhaust is so energetic and the little bitty difference in match up is not significant.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski