The 1963 and 1964 Max Wedge blocks had a different casting number than the 1964 and 1965 street wedge blocks did the M.W. blocks had 1/2 inch swinging oil pickups also and the street wedges had 3/8 staionary pickup just like all of the other non M.W. B&RB blocks did back then. I did find one 426 M.W. block casting # with a 3/8 oil pickup in a late 1964 Plymouth Sport Fury or a regular Fury, I never got to see the car, just the block along with the heads, intake and other parts I bought at a garage sale I was a little upset when I got the parts home and dsicovered the oil pick up was a 3/8 instead of a 1/2 I was still real glad to get standard bore block that would take a power hone job with a torque plate and still be only .002 over stock