Heartland USA Wheels are Designed and Engineered to work with each of the Heartland USA Conversion Systems. 18" x 5.5" for the 180 in 40, 60 and 80 spoke. 18" x 8.5" for the Two-Five-O, in either spoke or Billet. Spoke for 250 come in 60 spoke only. Aluminum Chrome Billet wheel comes 18" x 8.5" in solid only. We do offer two differant billet hubs that will fit .75 wheel center section with 10 bolts or the 2.30 center section with 5 bolts. Check with your Billet wheel manufacture of choice for section size.