1986 mustang lx 5.0 stock

Just ran my car for the first time last weekend. Its an 86 LX 5.0 with a 5 speed and stock 2.73 rear gear. ALL STOCK and the rear needs rebuilt. Ran a 15.17. Checked the timing on the motor yesterday and it was at 8 degrees. So i put it at 12 degrees and started running 93 octane so I'm excited...