Who knows B bodies very well ?

you can use 340 mounts on a 360-or you can use 318 mounts on a 360 by adding a washer/spacer to the drivers side. but you can also use the /6 k-member and put the 360 in the 72 a body by using a pass side truck mount and bracket(thicker biscuit) and the 318/340 mount on thwe drivers side with normal a body biscuit.