Porting the stock Intake manifold (my write up)

[DPG]

On a other note,
For the larger displacement of higher lift cars there are other options as well.
Increasing plenum by way of a manifold spacer although you can't lower the bottom plate further in a C engine.
Enlarging the VISS system with bigger butterfly's although if enough displacement is reached the system becomes irrelevant due to the increased low end torque due to displacement.

Increasing plenum on the TB side, this works on C32A and C35A engines i make spacers for those and everyone is pretty happy with the result those spacers start to work when VISS becomes active in stage 3 (3300+ on the SOHC engines)

I've to find some time to do more testing on those spacers and dyno runs.

Bringing this back to life. Were you ever able to do any testing with stroker motors or higher lift cams comparing VVIS present, gutted, and deleted?