There has just recently been a discussion on this block in the DeTomaso Forum. Somewhat sketchy details suggest there may be a sturdy 400 block without the thin wall problems common to the 351C. The 400 block came with dual purpose bosses cast into it so it could handle the big block C6 case and the small block FMX case. Same apparently with the motor mount bosses. The correct block is rumored to be found only in 1973 400 equipped LTD's and wagons that came with the FMX. Rancheros came with the C6. To see this thread at the Forum, go to
http://realbig.com/pipermail/detomaso/2004-October/date.html
and view the "clevor motor" thread. Lots of info there.
To answer your question, it HAS been done, but....
Larry
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