Engine location with motor plates

I've got a 70 dart drag car. It's a 440 car with elephant ears mounting the engine to the frame rails. There's nothing wrong with the setup and it has run very well in the 10.0 -10.3 neighborhood this way for years & years.

This winter I pulled the motor and one ear was cracked at a water pump bolt hole. No problem, I had it welded up.

However, a few weeks ago another FABO member had a one piece motor plate for sale that I couldn't pass up. It's a nice piece and it's going to work fine for me. I like the idea of the one piece plate across the front of the engine.

Now, I could just lay the individual ears on the new plate, transfer the height and the holes and be very comfortable with that. Like I said, it's run fine for years & years with the motor where those ears had it.

But I just can't help but wondering where the engine really ought to be and checking it. Does anyone have any official crank centerline measurements of where it should be side to side? Or any other guidance, theories, rules on engine placement?

Any input is appreciated.