Rear End

im deployed so I will have to have my wife take a pic for me. I basically have a 340 spec car in my 318. I have spent the money to upgrade everything so Im hoping for 400hp which is why I was asking. A bolt in replacement would be preferred but my father and I have been drag racing for years so he might know how to cut in grind he did his rear end before I was even born haha. I am also upgrading the suspension all the way around and installing 4 wheel disc brakes so newer bigger tires are definitely on the list of to do's. Thanks for all of the help. Any other Suggestions?