I want to buy a posi unit for the front end of my truck. Will a regular posi unit fir in the housing or are the inside dimensions different. Also is the front 28 or 31 spline axles. I have an 02 F-150 4.6 with 8.8 front and rear

 

Anyone out there????? I can't call a shop and ask because I am in Afganistan, so I was hoping someone here had the answer.