[Trochoidal]

This may or may not be helpful and it’s nothing special just some reference information in one post.

Wheels & tires

SS - OEM tire size
(front) 245/40R20 - 27.7x9.7R20
(rear) 275/35R20 - 27.6x10.8R20

SS 1LE & ZL1 OEM tire size
(front) 285/30R20 - 26.7x11.2R20
(rear) 305/30R20 - 27.2x12R20

ZL1 1LE
(front) 305/30R19 - 26.2x12R19
(rear) 325/30R19 - 26.7x12.8R19

Custom size - human29 setup
(front)285/30R20 = 26.7x11.3R20
(rear)335/30R20 = 27.9x13.2R20

https://www.camaro6.com/forums/showthread.php?t=546776

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Non-Factory stagger for SS 1LE replica
F 20x10 25mm offset. 285/30/20
R 20x11 43mm offset. 305/30/20
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Factory stagger for SS 1LE
20x10 20mm offset
20x11 43mm offset
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Factory stagger for ZL1 1LE
19x11 11mm offset
19x12 41mm offset

26" + Tire Diameter

245/35R20 = 26.8x9.7R20
255/30R20 = 26x10R20
265/30R20 = 26x10.4R20
275/30R20 = 26.5x10.8R20
285/30R20 = 26.7x11.2R20
305/25R20 = 26x12R20
315/25R20 = 26.2x12.4R20
325/25R20 = 26.4x12.8R20
335/25R20 = 26.6x13.2R20
345/25R20 = 26.8X13.6R20

27" + Tire Diameter

275/35R20 = 27.6x10.8R20
285/35R20 = 27.9x11.2R20
295/30R20 = 27x11.6R20
305/30R20 = 27.2x12R20
315/30R20 = 27.4x12.4R20
325/30R20 = 27.7x12.8R20
335/30R20 = 27.9x13.2R20