Since those three tests yielded very similar results...... there’s not much fun in that........
So, here’s three different intakes......

The motor is a 446 with dome pistons, stage 6 heads(owner ported) and a 280@.050 bracket race SFT cam.

First test is a TM7 with the spacer plates for the RB block and stage 6 heads, the Moroso 2” adapter and a 1090 King Demon(4500) carb.

The second test is my SD/4500 on the spacer plates, no additional carb spacer, same 1090 carb.

Third test is the MP full width Stage 6 4150 single plane intake(no spacers), with the 2” carb adapter, same 1090 carb.
(Where did the TQ go??)

Last test, pulled the 1090 and adapter off and installed customers Demon 850, no additional carb spacers.

All the full width Stage 6 intakes have MW sized runners. There are 4 versions.... 4150 and 4500 for both std and MW size.
Even the one for std port heads and 4150, like what was used for this test has MW sized runners.
The difference being that the port exits at the gasket are shrunk down to std port size on the ones for std port heads.

As you can see...... the ports CSA changing in size from MW size in the manifold down to std port size in the heads can do some strange things to the power curve.

The SD/4500 was the winner of this shootout