Ax10 with Vaterra Ascender shell???

[voo2doo]

I have an original old Axial Ax10 and to be fair it has seen virtually no off road.I have seen you guys running your scalers and decided to give the old chap a makeover.I bought a Vaterra Ascender shell but the wheel base is a bit far out.
The Ascender's wheel base is an adjustable wheelbase lengths from: 12.36 in (314mm), 11.9 in (302mm), 11.4 in (290mm) and 10.95 in (278mm). And the Ax10 's are 304mm-320mm (12"-12.6").
Can anyone here tell me what I would need to make the Ascenders shell fit the Scorpions chassis?
Thanks
J