While I would think the largest resale audience would be if you leave it with a Ford small block in it, there is no guarantee that it would be worth more money than one with a Chevy motor. It is your car, and your decision.
If this blog is correct, the highest selling price for a Ford era Pantera was paid for one that had a Chevy LS engine in it.
http://ringbrothers.com/blog/BarrettJackson2015/
On a technical note, I discussed with both Les Gray and Roy Butfoy about running supercharged horsepower in the 600-650 range thru the ZF and neither were too concerned. Les said the most likely failure would be in the higher gear. I cannot remember if he said 4th or 5th gear. Drag racing and speed shifting has broken ZFs in the past.
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