Hi actually you have two types, Turbines and Turbine II rims. Both are very desirable and the caps are extremely difficult to find. The Turbines were a option on many 1979 AMCs, but were part of the 79 AMX package: http://www.planethoustonamx.com/parts%20&%20Literature/79_amx_pr.jpg They also appeared on the slow selling 80 AMX: http://www.planethoustonamx.com/parts%20&%20Literature/80_AMX_PR.JPG There is also a very similiar rim by American Racing rims that looks identical to the AMC rims. The Turbine II rims were a $356 option on Spirit GT, and I believe $341 on DL and Limited versions (give or take a $). Expect to pay about $400+ for a set of nice ones, with or without caps. I had a set of nOS caps two years ago and sold them for $200, again the caps are just as hard, if not harded to find than the rims. Good luck, Eddie Stakes' Planet Houston aMX www.planethoustonamx.com