Just a question......why would you need spacers for aftermarket wheels? they should bolt on no problems. Only time I have heard of spacers needed was putting factory 05 or newer wheels on 04 or older superduties.
I used to have a 91 F350 that I bought these rims for and it was an 8x6.5 truck. So now I have the 8x170's and need the adapters to make them fit! The only issue is the offset, I may need to get wheel flares to keep them looking right.
My 4 door long box fits in my garage with JUST enough room for me to shimmy sideways between the back bumper and the door. Height wise, I think I have about 3/4 of an inch. Lets put it this way, unless I shovel the snow in front of the door, it won't go in.