Alot of questions here....I am not a expert of 4 speeds but bellhousing for sure....pressure plate and clutch probably need to be changed....I am pretty sure you will not have to drill out of the end of the crank...I believe most cranks out of the box were made to mate to the snout of the torque convertor or a pilot bearing...you should go the Schumacher route and include their headers...life made easy and you will probably have to get a modified z-bar from TTI