Are all suspension parts between GMC and Chevy truck identical? I put my truck back together using the lower control arm, spindle and rotor from an '87 GMC Wrangler with the top control arm and frame from an '87 Chevy R-10. I noticed the GMC had 1/4" wider rotors than the Chev, but the rest looks identical. I'm certain I put the shims back where they were supposed to go, but the wheels are still slanted inward at the tops. I Realize that and alignment is required, but how many shims can you put in?? Is there a heavy half ton in these years? What happened? Any advice would be really appreciated.