73-87 GM a-frames (control arms)on pre 73 2WD trucks

[norv struckman]

Who has taken some accurate track mesurements before and after this retrofit to determine if the track actually increases (which is what I've seen written elsewhere on this forum). What is the measured increase? I don't want to use the wrong modular dropped spindels (there are two versions one for each generation of a-frames) and lose any of the advantage of narrowing the track by changing to the newer GM A-frames (control arms). What about spindle arm/tie rod end interferance with the inside of an aftermarket 8 inch "corvette" style rally wheel (5 on 5) with 4.5 inches of backspacing? I'll need 1/8th inch of clearance between the wheel and the head of the tie rod. I know 5 inches of backspacing with the same style wheel won't work with the stock GM a-frames on my 72 2WD blazer. I ruined one tie rod by "massaging" it with a die grinder to create clearance, bad idea! Advise thanks, norv.