Rims/wheels for 83-87 C10

[41willys]

Anyone have thoughts or experiences to share on the BOSS 338 or Ridler 695 rims or wheels for the 83-87 C10's? I plan to do a static drop 5/5 and looking into either an 18" or 20" rim. I need some help with "offset" and or backspacing for these rims. I finally woke up after I had already posted on the '72 page about this issue and discovered that I had done this. Talk about the BOSS 338 center cap not fitting flush due to the dust cap/rotor hat length. I have the 1.25" rotors on my truck and from what I read if you have the 1" rotors the 338'S fit fine with not issues.