4 speed tunnel position question

I did the same thing rocky did I bolted tranny to the block and dropped in the car and bolted it up then cut a hole for the shifter and centered the shifter in the
the 4 speed hump and marked it for position. There isn't a whole lot of room for error on placement of the hump so if at all possible I would get the engine and tranny in before hand if only long enough to position the hump