The Olds 350 is a great motor. Bore it .068 or .100 over with 400 chevy pistons and rods. You will have 380 cubic inches with small journals and offset grinding. A 455 Olds is also a fairly easy swap.
88 Cutlass Supreme Classic, Mild Olds 350, 2004R, 3.42 open for now....94 chev Z71 4x4, TBI 76 350 Olds, 5A heads,A4,204/214 cam,Sanderson's and duals, rebuilt 4L60E,3.73 gov lock, 2010 Challenger SE, Stone White, leather, 18" wheels, 2000 Dodge Dakota Sport Club Cab 4x4, 3.9 v6 and 3.92 no slip.