Alignment tools for Bravo 1 and Bravo XR drives are the same. The portion of the alignment tool that inserts into the coupler spine does not have splines itself. The outside diameter of this section of the shaft is approximately the same as the inside diameter of the coupler splines. The most accurate way to establish proper engine alignment is by using the correct alignment tool.
It is possible to make a make-shift alignment tool using an input shaft from a drive. In order to do so, you must be certain that the shaft is straight and not twisted. When the drive is installed, the shaft is inserted nearly all the way to the gimbal bearing which would make it difficult to use as an alignment shaft by itself. If a bar was welded on the u-joint end of the input shaft, it would work OK as long as the splines in the drive coupler are not worn.