15x10 Rim backspacing help on 4 corners
 

So in a little bind here. Long story short I need to replace my rims through insurance due to a fire in the back yard.

My truck is in a million pieces and cant measure for back spacing. Insurance says it has to be a 15 inch rim and steel but don't say nothing about width. I want to run 15 by 10 wheels on four corners. The truck is gonna be low like 4/6 drop or 6/8 even. So its going to have 2.5 drop spindles for sure.

Was thinking of one of going with one of these
https://www.summitracing.com/int/par...5150/overview/
https://www.summitracing.com/int/par...5042/overview/

Oh and its a 68 chev c10 so it got the narrower axle by that inch and a half. Any help is much appreciated. Thanks