I have the opportunity to purchase a 390 2V from '61, '63, '64 or '67. I have read and heard of differences among years for quality of block for boring and material used for crankshafts. Does anyone have a recommendation as to which would be best? I plan to put it in a '64 Falcon, mostly street and show but would like opportunity to race. Modifications would be limited to stock parts where possible, cam, compression, intake and headers, looking for a stock type appearance.