Car has been in family since 94 so i dont want to get rid of it but the motor was knockin and heads went out on 3.8 so i want to put 5.0 in it..just want to know what parts i need to complete already have engine just need to know other conponents
Is this something you want to half ass, or is this something you want to complete over time?
To me, sentimental value can get you in a lot of trouble. This is obviously a 1 owner vehicle, but you swapping or changing anything on it, is going to depreciate the value of it.
If its that sentimental, just find yourself a 94-95 GT, and swap everything over. You will have the whole harness, cluster, motor/trans and all. You can find a running one, beat up body for around 15000-2000. You can find one that had rear end damage for less than 800. You have tons of options, it just depends on how mechanically inclined you are, your time frame and how much money your willing to spend.
Personally, what I would do if I were you, rebuild the 3.8 or find a used one and replace it. Save the money you would be spending to swap everything over and just buy yourself a nice SN GT.
Also, this would be in the wrong section, as this is for Fox Bodies

This is the section for the SN guys. They have a different section, because their cars are hideous
http://www.stangnet.com/mustang-forums/forums/94-95-tech.66/