Opinion wanted on Percy's Wheelrite simulation

[Turbo67camaro]

I'm looking for more educated opinions than mine if I've got this Percy's wheel simulation tucked in far enough, or do I need to increase the backspacing a bit more. If so, about how much more?

The Wheelrite is in the vertical position. It is set to 4.75" backspace, but I'm allowing for a ~.25" tire bulge outside the rim, so the wheel would be 4.5" backspace, 8" wide, 18" wheel. Plans are to use a 245/40/18 tire. Wheelrite wire simulating tire is set to 9 5/8".

Marcus at SC&C recommended 245/45/17 with 4 to 4.5" backspace, but I decided to go with 340mm (13.4") brakes which require an 18" wheel and 245/40/18.



Related info:

67 Camaro
Alignment is not yet set (to my knowledge, but my builder may have ballparked it)
SPC Upper and Lower Control Arms
ATS AFX tall spindles
Z/28 short steering arms
C6 Z51 340mm Brakes
Eibach springs (1" drop if I recall correctly)
Standard height solid body mounts
DSE subframe connectors

I need to install some kind of steering stops to prevent subframe rub, as I think the SPC lower control arms allow steering to turn farther than stock lower control arms. To prevent subframe rub without steering stops I'd need to go with a backspace close to 3.5", which is totally non-standard, and the tire won't be tucked in under the fender.

You can't tell in the picture, but there's still a lot of vertical fender clearance, as I have a fair amount of weight to install in the front end yet.