Have you ever done a swap? You say you hate doing elect to go efi like youve done it before. Why not just sell the 83 for 1k, save up 2k and buy a decent fox with a 5.0. Save some money and you and your dad a headache.
Dosent 4cyl fox bodies have a 7.5" rear too, and that t-5 in the 4cyl wont bolt right up to a 5.0