You don’t want to add a 1/2” spring offset kit? Now would be the time to do before welding your perches. You have a better selection of rim back spacing if you do and looking at your pictures would align the perch right over you weld on the axle tub.
Car this is going under was hack minitubbed, going back stock width. Using fifth ave 15x7 steelies all around. Honestly i dont know how much your really gonna get out of a 1/2" offset kit especially with the rim size i got going under there.
I dont think it would align it right over the tab if thats what you mean? Theres a lot more than 1/2" between the perch and the weld on tabs for the brake hoses