Chassis shortening

[Zetomagneto]

John,
You could take 6inches from between the cross members as shown here. Also perhaps box the chassis below the joint for additional strength.

That looks awful, ruination of a chassis.
Not difficult to shorten a long chassis properly, note the 6 " has to be cut from the ends of the sidemembers, not in btween because the chassis section tapers along it's length.
The rear crossmember will also have to narrowed, best to take the excess out of the centre where the torque tube anchorage is fastened.
I have seen narrow chassis with wide axles In them or you could get Andy Bird to narrow your casings and half shafts