Factory: the 70-71 have a low intake and heads and wont interchange with 72-6 heads intake, how ever, a full head and intake will interchange just cant mix and match between 70/1 and 72-6. After market intake will cover holes in water jackets for 70-1, follow intake gasket for appropriate years heads. Oiling pre 71 is in journals, 72 on oils thru lifters and push rods. Valvecovers all fit 430/455. use a carb about 800cfm + I used a 875 cfm Holley with fantastic horsepower. Oil galleys in early years suck, must be drilled to 5/8" oil pan to galley and front galley to rear. use late pick up tube on pan to 5/8", use high vol oil pump on all buick or high pressure kennebelle pump using 70 or earlier front cover. Buy the book " guide to buick performance" by Dove at local book seller . Best book for buick motor builder.