spacers for 205/15, J7 wheels

[Martice]

Hello,

I have some 15", J7 Zender wheels, with some 205/55 tyres and its time to fit them on my '71 1302. After my calculations they will fit with some 40mm spacers.I plan to make the spacers from alloy at a local machine shop.

after other calculations , the wheels will be about 3cm out of the stock fenders... I plan to go for +3cm fiber glass fenders.

Does anyone see any problems with the 40mm spacers??? or other problem I might have?

Martin