I used urethane 4-link on on a 30 A-bone sedan, full-fendered steel, 9" Ford w/ 4:10 gears, top-loader 4-speed behind a 454 Chevy. Rode like a slot car, and ran high-11s / low 12s on street tires. Never had a problem. Dave is right. Use good un's from someone like Pete & Jakes or So Cal.