1978 GMC Caballero Bore: 2.50 In.; Position: Front;. 1979 GMC Caballero Engine: 3.3L V6; Bore: 2.50 In.; Position: Front;. 1979 GMC Caballero Engine: 5.7L V8; Bore: 2.50 In.; Position: Front;. 1979-1982 GMC Caballero Engine: 3.8L V6; Bore: 2.50 In.; Position: Front;.