I just got a Mark VIII with an OK body and was looking to transplant the engine into a 1995 Mark VIII that had a freid drivetrain and better body.

I've read that there is an ignition chip/theft interlock on the steering column that is linked to the ECM. If this is true, how does one go about transplanting a motor and ECM and get past this theft/safety interlock?

So a 95 into a 95?

You can not put a 96 and up ECM into a 93 to 95. But you dont need to. The info you got would be wrong for a 95. There is no PATS system until 97.

I'd be swapping the 93 motor into a 95. so from what you are saying I should have no problem swapping out the motor and keeping the ignition and stering column in the car? I know..I'm a bit slow here.

Yes, that is correct. 93-95 are the same.