Wheel Spacers

[davidtite]

Hi,

I have a Porsche Boxster S 2001 MY.

I currently have the following wheels on it:

17" Porsche Sport Classic 1 Alloys

SIZES:-
ALLOYS:- FRONT, 7J X 17J. REAR, 8.5J X 17J.

OFFSETS:- FRONT, ET 55. REAR, ET 50. P.C.D. 5 X 130.

I have bought the following and want to fit them to my Boxster (I beleive they were off a 911)

18" Porsche Sport Classic 2 Alloys

SIZES:-
ALLOYS:- FRONT, 7.5J X 18J. REAR, 10J X 18J.

OFFSETS:- FRONT, ET 50. REAR, ET 65. P.C.D. 5 X 130.

What size spacers do I need?

I belive the front are ok but I am not sure about the rears?

Thanks