You could even make a 273 into a cheap MPFI engine by bolting on intake and beer-keg intake, and add the Magnum flex-plate w/ "toner ring". You cut a hole in the transmission bell-chamber to fit the crank sensor on a bracket (search photos). Could also bolt on a Magnum transmission, which gets overdrive, but must reform the trans tunnel for clearance.
You'd have to swap cranks or modify the (early) 273's crank flange to fit the later OD transmission- remember, all pre-'68 engines had the smaller register for the convertor snout.
