HELP!!!Before I open my CSP disc brake kit for my bus!

[bigbrownlabrador]

Help please.
My son has a 63 kombi.
It has 15" rims and he intends blast em and paint em and to keep them.
He has purchased a narrowed 2" adjustable front beam.
He has also purchased CSP 205mm front disc kit.
He wants to lower his bus a bit, install the discs, use his 15" rims with a very low white wall profile tire.
CSP's pamphet says we cannot use the stock rims. We've done a test fit and this seems to be the case.
Can we make this set up work with the use of spacers to push the rim out for the caliper clearance?
How far out?
Is it safe?
With it lowered a bit will they rub?
OR should I take it back and get the 14" set along with smaller rims?
Thank you.
Doug

[KILLERWATT]

I would call just to make sure, but I think when they say stock rims they mean the 14" rims. If you have early 15" stock rims you should be good.