All,

I purchased the smoothing plate from Mike's custom cars. Where the existing heater core went and the blower motor there are ribs sticking out to hold those parts. I assume that I need to pound those flat? What's the way everyone else did this?

Thanks

Yes. I bent mine flat with vise grips and hammer & dollied it smooth then welded my plate over it. When you weld your plate think about some plug welds to help reduce vibrations.
Click my signature link I have a bunch of pics,I'm ready for paint on mine. good luck.
Jeoff J.