273 Supercharged...ITS HAPPENING PEOPLE!!

You should check your comp ratio while you have it apart and try and raise it to the safest level you can with the boost your using, Check the cam profile too. If you stick with the 727 auto ( poorest choice in my opinion) then you will need a custom torque converter.
Running the 727 and the blower is going to put load on the engine from the get go, so you need to produce as much low end as you can to compensate or it may not like to idle in gear or be a real slug down low until you build some boost, which is typically only up in the higher rev ranges with a centrifugal blower.