318 poly wide block

On the clutch, no, sorry. If you could get pictures ..... where's @RustyRatRod ??
He would probably know this!

The older A engine is sometimes called wide block because of the Mirage created by the style cylinder head & the odd look of the intake manifold.

I did a major posting on this years ago in someone's thread. I had the two blocks side by side.

If you weren't a MoPar guy into playing with blocks or at least slick enough to catch the small details you would not know the difference between them. It would take a close look.