Ok, so it's a little difficult for you to see, but at TDC these cast slugs are about .034 down in the hole. I've got ideas on improving that, from free to $$$$.
First, take the pistons out and swap them side to side. That will move them up in the bore since piston pins are offset. It's an old school trick, but probably only worth about .010 to .015. This might result in some cold startup piston slap, but it's not a BMW It shakes, rattles and rolls as it is.
2nd, replace the pistons. I've seen a set on Ebay, Hyper with moly rings for about $200 that will move the piston up about .014 iirc.
3rd I could put those pistons in backwards...that should get it up in the .025 neighborhood.
4th have the block decked, with new pistons. I am not decking it for cast pistons.
5th Get a 393 or 408 stroker. Probably 393 (or whatever .060 over makes it) and reuse my rods, IF they are truck rods.
Really option 1 or 2 is pretty much my limit, especially if I want AFR heads. Maybe just 1 and some moly rings and a dingle ball hone job.
It's also amazing that ANYTHING in my garage becomes a shelf. I used that Romex last year about this time to put a 4 ft flourescent fixture in my attic. I bought the toolbox line at least 18 months ago and had that leftover. I was wondering where those gloves went!!