Part Type: Accessory Drive Belt Idler Assembly. 1975 Ford E-150 Econoline Engine: 5.8L V8; Factory Installed AC;. 1976 Ford E-150 Econoline Engine: 5.8L V8; Factory Installed AC;. Idler Assembly. 1977 Ford E-150 Econoline Engine: 5.8L V8; Factory Installed AC;.