It took a minute to figure out what an 'engine plate' is. I'm assuming it's for your hoist, to lift the engine.
Here is the first one that comes up:
Buy Engine Lift Plate Compatible with Ford Windsor 5.0 5.8 302 351 W V8 EFI Made USA Hoist Lifting Crane Lift Picker Massive Speed V8: Engine Hoists & Stands - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
Of course there are many others.