Thanks fellas for digging out these examples. Clearly Lincoln and Mercury didn't share their frames. The Merc still had a ladder frame so that version certainly won't fit! It led to a decent Google about the different frame configurations over the decades. Quite educational.

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Yep, that's the troublesome bit, right in the centre of the diagram.

As mentioned, the way I would go about it is cutting the tube  @ the inner frame rail and welding pates on either end to fit within the rails exactly. I would also fabricate an outer rail plate to sandwich the the rail as it will have been weakened having removed the welded tube and having the open hole in the rail(s). Use GRADE 8 cap screws with shoulders and the proper torque value with possibly pals nuts to keep the frame rigid.

You would just have to figure if the cross-member will drop out or has to be slid rearwards to clear the trans.

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