I hope not to highjack your thread, but what are you building? I'm assuming you are talking narrow body setup. Also, is the dimension you seek = track width plus or minus wheel offset?
Rear Track width: 1500 mm (59.10 in) with 17″ alloys, 1480 mm (58.31 in) with 18″ alloys
225/40 ZR 18 – 7.5J x 18 – 50mm offset
I found this info. Based on the above I think the dimension you seek is 63 inches. I got that from the track width of 59.1" and adding two times the 50mm offset. 100mm = right about 4 inches.
Again, what are you building? Here is my 74 Super Beetle which has some porsche parts.
https://preview.ibb.co/gSwNQx/93_BEC9_B5_56_CF_487_B_8771_9_A24066_DD44_A.jpg
https://image.ibb.co/dDkMTS/B319_BD2_E_C87_D_4_CD5_80_AB_188_B6_C7792_A1.jpg
https://i.ibb.co/0tj2CkN/5-CE8244-F-5113-4-CCC-9963-F979-EDEF61-CA.jpg
It's on Volksrods.com if it interests you.
What are you building?
