Won't fit. Two different bellhousing-to-block bolt patterns. And the T-45 has an integral bellhousing, whereas the T-5 has a separate bellhousing. You would have to buy an adapter plate to fit a T-5 bellhousing to a Modular block, if such a part even exists. Then you would need a flywheel with the correct balance for the Modular engine, but small enough to fit inside the T-5 bellhousing and with the right tooth count, and a clutch with the correct spline-count to fit the T-5's input shaft.
1979-1993 Fox Capri and Mustang VIN Decoder: foxchassis.com
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