These are the correct dimensions for the TD/Rimstock wheels, trouble is the 9 mm change in offset, new wheels should be 63 mm offsets just to position rim with same backspace distance as the OEM rims but as BRG points out the A-arm is tapered so even with that, 63 mm on an 18" wheel will cut down the distance 'tween rim and arm, maybe a 65 mm offset or 5 mm spacer is ideal with an 18" rim... Also, I thought that the recommended wheel sizes by VSA were these:
fronts: 18 x 8.5, 52m offset, 5 x 114.3 bolt cir, 68.1 center
rears: 18 x 10, 60mm offset, 5 x 114.3 bolt cir, 68.1 center
BRG, how deep is the groove? if you measure its depth (parallel to axle shaft) and add 2mm for comfort clearance that is the spacer width needed. Maybe only 3 mm is really needed, in which case lugs should still work.