i'm at the tail end of of a m180 to 127 engine transformation for a 1963 220s

the m180 had a cracked head which i could have brought to a machine shop but i would then be concerned with the block, pistons, etc and it wasn't worth spending close to 5k rebuilding.

i bought a recently rebuilt 127 engine for $700.

things to be concerned with

1) how long was the engine sitting?

2) manual or automatic - pilot bearing and how the flywheel bolts onto the tourque converter

3) electric fuel pump - needs to added near the gas tank and needs to send 18lbs of pressure.

4) wiring - the fuel injection engine has more electronics involved.
i have diagrams if you need

it took more time than what i was originally expecting but i am overall very please with the results.

everyone here has been extremely helpful (see link) [link]http://www.peachparts.com/shopforum/showthread.php?threadid=56938[/link]

you could do it
don’t give up