The issue is the transmission itself. There are two different 4L60E designs, the newer of which uses a pulse-width-modulation control of the TCC, and these are not interchangeable. It was around '95 or so that the PWM came in to being, possibly earlier.
If your PCM is for the 2005 model, the older trans (if it's not PWM capable) will not work. The PWM front pump should have PWM embossed on it.
Inasmuch as the flex plate is concerned, it should work with either.
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1988 9C1 - Modified LM1 @ 275HP/350TQ - TH700R4 - 3.08 8.5" Disc Rear - see it at
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2005 Crown Vic P71 - former AZ DPS - 4.6 liters of pure creamy slothness!
1967 El Camino L79/M20 old school asphalt raper
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