15X5 4"bs fit 95 TA?(+few other ?'s)

I know a 15X5 3.5"bs will sit about where a stock 16X8 would. If I get a 15X5 w/ 4"bs, it would move the wheel in under the fender a little more. Would Centerline Telstars or Convo Pros fit an LT1 fbody in 15X5 4"bs w/out any caliper grinding?

What's backspacing on a 16X8?

What's frontspacing? Is there a way to figure it w/out actually measuring it, like using backspacing or something?

Thanks!

its not going to work, will hit the knuckle

If a 4"bs hits the knuckle, a 3.5"bs will require caliper grinding?

So no weld over 3.5 bs regardless of width fits Fbody front? But a 3.5/4.0/5.0/6.0/7.0 width with 3.5 or less backspace will fit??