6 cyl a230 ?s

Nice Basin Street Blue Duster in your profile! I take it that's the car for your goal? Is the four speed within the reach of your budget? If you can live with deep rear gears, the close ratio a230 from a 340/383/400 car may put the goal within reach with a small block. But the wide ratio will work with a small block if you don't mind carrying some extra atmosphere in a bottle, or if you have access to a 383/400 B engine on the cheap...