Author Topic: Mark IV Big Block exhaust manifolds  (Read 3743 times)

crossboss

  • Hero Member
  • *****
  • Posts: 779
  • ^ New engine project
    • View Profile
Mark IV Big Block exhaust manifolds
« on: November 07, 2019, 04:47:51 PM »
Boys,
Need a bit of advice/help on this one. What Mark IV Big Block cast iron exhaust manifolds flow the best with square port heads. I am not chassis restricted, so no worries there.
Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)

firstgenaddict

  • Hero Member
  • *****
  • Posts: 2882
  • caretaker of 1971 LT1's 11130 & 21783
    • View Profile
    • Groome Family Automobiles
Re: Mark IV Big Block exhaust manifolds
« Reply #1 on: March 31, 2020, 11:56:50 PM »
The corvette style are the better cast iron "manifolds".
 The 4 branches come together more like the old SD pontiac "header" exhaust manifolds on the 421's.
James
Collectin' Camaro's since "Only Rednecks drove them"
Current caretaker of 1971 LT1's - 11130 and 21783 Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

crossboss

  • Hero Member
  • *****
  • Posts: 779
  • ^ New engine project
    • View Profile
Re: Mark IV Big Block exhaust manifolds
« Reply #2 on: April 09, 2020, 06:33:34 PM »
The corvette style are the better cast iron "manifolds".
 The 4 branches come together more like the old SD pontiac "header" exhaust manifolds on the 421's.




Thanks, much appreciated!
Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)

firstgenaddict

  • Hero Member
  • *****
  • Posts: 2882
  • caretaker of 1971 LT1's 11130 & 21783
    • View Profile
    • Groome Family Automobiles
Re: Mark IV Big Block exhaust manifolds
« Reply #3 on: April 20, 2020, 03:25:59 PM »
You could "EXTRUDE HONE" them as well...
James
Collectin' Camaro's since "Only Rednecks drove them"
Current caretaker of 1971 LT1's - 11130 and 21783 Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

crossboss

  • Hero Member
  • *****
  • Posts: 779
  • ^ New engine project
    • View Profile
Re: Mark IV Big Block exhaust manifolds
« Reply #4 on: April 20, 2020, 10:45:41 PM »
You could "EXTRUDE HONE" them as well...



Yes, that was also in the plan to do list.
Just another T/A fanatic. Current lifelong projects:
1968 Olds 442 W-30
1969 Mustang Fastback w a Can-Am 494 (Boss 429)

 

anything