They are needed for rim clearance. the back spacing on a mustang wheel is very different than that of a truck. If you were to bolt the cobra wheels straight to your truck, they would be tucked way under the wheel wells, and would conflict with the shocks/springs/brakelines/etc. Also, the center hole of the cobra R wheels will not clear the hubs on the front axle. I am not sure what the wheel spacers go fo these days, but I paid 150$ for each of three pairs. As mine are used, and are not in the most perfect condition, I'd take $150 obo for all six (three pair), plus shipping.
here are some pics of my truck when I had the Cobra R wheels on it.
Dead Link Removed
[Edited by Mudd***** on 01-30-2001 at 08:28 PM]