The car is an 89 mustang 5.0 HO. I was wondering if you can install the pump driveshaft and distributor at the same time, and how do you know if it's properly engaged in the oil pump?

 

So nobody doesn't know anything about oil pump driveshafts?

 

Yes, you can install the oil pump drive shaft at the same time as the distributor.The retaining clip (star washer)will have to be removed. Also make sure that you are using the proper 5.0 shaft with the EEC distributor. You can't use an old 289/302 shaft because the tip length is different. Since the shaft, pump and distributor all use a hex shape it can go together six different ways, it will be difficult to align the rotor and may take several adjustments. Plus the shaft will want to fall up against the block away from center, I've used a dab of grease to hold it in place.