what changes were made to the Gillig chassis when SMC acquired it and made the Magnum D-series?

[BeaverOwner]

The Gillig chassis used on the early Beavers was described as "a Raised Frame Rail, 8” x 3.5” x .25” U-Channel - Double Flange, Huck-bolted, using SAE 410 grade 960 Steel Stock." This has been touted as very strong frame and desirable to have.

Then

In 1997, a new chassis was developed for the Beaver Marquis. Previously, the Marquis was constructed on a purchased Gillig brand chassis. Gillig ceased production of the chassis in 1997. Magnum acquired the rights to manufacture the chassis from Gillig and, after making some modifications for the Marquis' specific requirements, now produces the chassis at a lower overall cost to the Company.

That new Marquis chassis was the Magnum Series-D "Blue Diamond".
Quote taken from SMC's 10K report

However the Magnum D-Series “Blue Diamond” chassis which uses a 10.25” high, schedule-50 high yield steel frame rails. And the Gillig uses 8" tall frame rails.

The quote says "some modifications" were made - however changing frame rail dimensions seems like a "major change" to me - so I'm wondering if anyone knows exactly what changes SMC made to the Gillig chassis when they turned it into the Magnum D-series chassis. Conversely, what design elements did Magnum use/keep from the Gillig design?