Considering the size & rpm, interesting that the headers started at only 1 3/4" & stepped to 1 7/8'. Probably to help keep the average HP up.

Just for comparison, does anyone know how much HP Glidden's Arrow was making once he got done with all of his tricks? I believe his engines were somewhere in the 320 to under 340 cu. in. range.

The windage control tricks are cute, but how are you going to mount a trans to that with the oil drain line in the back of the block?
Looks like a purpose-built dyno hero.

The article seem to suggest a or range of years that the Magnum block was best. A .1 overbore on a stock Magnum block seems iffy to me. Were the cores of those blocks mentioned that much stronger and consistent with the castings? I'd also be interested is seeing that valley strengthening component.

There were suppose to be some early Magnum blocks that were cast and drilled for shaft oiling. That block appears to be one of them.

Can't tell if the heads took advantage of that or the rockers were oiled through the pushrods.

1988-1992 5.9l/360 were supposed to be roller cam, but block still drilled for shaft oiling LA style heads.

I imagine the partial fill with hard block probably helps stabilize the cylinders at the .100" overbore.