You may want to move piston #1 to 30 degrees BTDC and verify that the distributor is in correctly. The #1 cyl cap contact should be in the middle 3rd of the contact on the end of the rotor. If it's not, your distributor may be off a tooth.
Did you reset your computer after making all of those changes? If not, you probably should.
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351W 89 Mustang GT Convertible