Old Race 340 Teardown
See how there's an extra thickness of plate welded on top of the original cast flange, under the bolts? It looks like it's meant to stiffen the whole flange. I thought the same thing about port matching the W2 ports but since the manifold was specific to the W2 (as shown in the original Holley box picture) I am not sure that would be necessary.
I think this manifold is a carry-over from his 340 that was in the Valiant, which had a Paxton supercharger. Maybe it was insurance that there was enough clamping pressure to keep from blowing out the gasket? I know he was developing enough pressure to crush brass floats. The carb was inside a pressure box (on the Valiant, not the Duster, which was always normally aspirated).
See how there's an extra thickness of plate welded on top of the original cast flange, under the bolts? It looks like it's meant to stiffen the whole flange. I thought the same thing about port matching the W2 ports but since the manifold was specific to the W2 (as shown in the original Holley box picture) I am not sure that would be necessary.
I think this manifold is a carry-over from his 340 that was in the Valiant, which had a Paxton supercharger. Maybe it was insurance that there was enough clamping pressure to keep from blowing out the gasket? I know he was developing enough pressure to crush brass floats. The carb was inside a pressure box (on the Valiant, not the Duster, which was always normally aspirated).