Re: 1957 35 big twin won't come out of gear
Remove the oval plate on the side of the midsection and look in there. You will see the connector that joins the upper and lower shift rod. OK, now move the shift lever through the gears, while turning the prop. Does the shift rod connector move up and down and is everything coupled so that it moves the lower rod as it does?
The point in this exercise is to isolate the trouble and find out if it is a problem above or below that window. Then you go from there. If the upper rod does not move, the powerhead has to come off. If the lower rod is moving, but it doesn't shift, the problem is in the lower unit.