Seems to be a lot of material left in the intakes pictured.

My 420 does not have much work. I was told by the big NA guys I would be down 50 HP due to how much material is still in my 420. My plenum is quite a bit larger than the ones pictured. The runners are basically as cast with the exception of port matching and blending well up the runners.

It's too hot and I am too lazy to take some pics. Probably should sense they are for sale. But, someone will copy my unskilled work. LOL
The 598 I have was done by a local professional and looks really nice in the plenum but runs abouts the same as the others. At least one would not have to weld over any overcuts.

Leon