Okay, this is where you will need to take the convertor register differences that I mentioned into account. Depending on the year of your 273, a '67 and earlier crank will not properly mate to a '68 (the year small block 727s were introduced in pass cars, with the introduction of the 340) and later 727 trans and convertor because of the register differences. If it's a '68-'69 block/crank you should be okay.
