hey, I am new here and all this info on third gens os awesome. I am looking for a straight up answer. I have a 90 camaro with the old southide ladder bar kit(works great, 1.38 sixty last weekend) and 28x10.5(not w) on 10" with 5.5" backspacing. I run a 513 gear. I need new slicks for next season and want to know what it will take to get a "w" tire under my car with out extreme mods(do not mind cutting frame, just not installing tubs) any help would be great, thanks for the great site

A W tire is pretty wide. With a bunch of inner fender modifications, I was able to squeeze a 29.5 x 10.5 under the fenders on a 15x10 rim with 5.5" backspace. I doubt a W would have fit without a fit more modifications with a BFH.

A 29.5 x 10.5 has 10.2" of tread and a 13.1 section width.
The 29.5 x 10.5W has 11.2" of tread which to me shouldn't qualify as a 10.5 tire and has a section width of 13.6" wide which only puts it 1/2 inch wider than a non W tire.

I ran those tires for 2 years then back halved the car and now run 32 x 14 tires.

You need to do something like this until you get enough clearance.