Chrysler Engines

I copied and paste this reply from an old thread that this subject was discussed. This is a real life experience I had and not some "theory." Just so you can make an informed decision on weather to drill or not drill a crank.
From 9/12/11

There is a good reason why you can't or shouldn't drill the 440 cast crank to acept the 4sd imput shaft. in the early 70's i worked at a shop that did all the repair work on Hillsborough county sheriffs cars. We bought rebuilt engines from a company named Wheeler Engines. They had the bright idea to drill all the 400/440 cast crank engines so they only had to carry one part number for auto's or manual shift cars. But it turned out to be a bad idea. The cast crank castings were so pourous that oil would leak thru tha cast cranks and out of the drilled holes. I was unlucky enough to install one of these engines and went through hell trying to figure out why this new motor had a rear main leak. I figured it out and by then Wheeler had a recall on all of these drilled cast crank engines.