the 472/500 Caddies with a main bore that is huge at 3.4383-3.4390 which doesn't leave much material between the main bore and the cam bore for strenght, has real skinny wings out to the outer walls and puts 2 vertical oil passages for a place for the main to split out---It is not an engine I would use/recommend for big horse power---

Now, if---you were going to make a one piece griddle/main cap that used the 10 bolts Plus the oil pan bolt holes---then doweling the girdle to the block at the main bolt holes would be a route to take----------

With that, I'll back out of the main cap discussion as I have said my piece, speaking from my past and present experience---

I'm sorry, but it seems that every time I get involved in this thread, I probably come across as a nit picker---