Here is my personal experience with the Indy cloverleaf.
When I still had it. Car ET’d and MPH’d better with carb right on the manifold.
I removed it but never actually got a chance to test that way other than the dyno.
On the dyno the fuel numbers were all over the map with it removed.
Now was this because of the manifold or the other heads and cam I had on the motor?
That I am not sure of.
Before I did any actual track time I sent the manifold to Wilson for a full competition port.
Never dyno’d the motor again but here are this years results.
Before cutting cloverleaf out, running carb direct to manifold with a heavily ported EZ-1 that had
2.25 intake valves, the car ran 10.12 @ 133 and change with a 1.42 60. That was a 4.30 gear.
This year the combo is the same except I have 4.10 gears and mild ported EZ-1 with a 2.19 intake valve.
The Ported Wilson Manifold has a 1” taper spacer and the same carb as before.
Car ran a best of 10.10 @ 132 and change with a 1.38 60.
Now is the manifold Work offsetting the smaller head? Is the 4.10 a better combo for my low gear set in the 727?
Is it a little of everything? Probably.
With the wild fuel numbers I got on the dyno, I am not sure I would remove it without doing other work to it?
Simply squaring it off I think is a step backwards. A proper blend is needed too.
Talk to Wilson. It is expensive but so far I find it was money well spent.