Mark IV Big Block exhaust manifolds

[crossboss]

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.

[firstgenaddict]

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.

[crossboss]

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!

[firstgenaddict]

You could "EXTRUDE HONE" them as well...

[crossboss]

You could "EXTRUDE HONE" them as well...

Yes, that was also in the plan to do list.