school me on stroker smallblocks

Most stroker rotating assembly kits are available with optional balancing and all the kits I looked at were internally balanced. If you don't get the optional balancing you still get the same pistons/rods/crank as the balanced kit would have. So if they offer the option to internally balance the kit but you buy it without that option then you should be able to have it internally balanced by a local shop without issue.

What Scat did with my "balanced" kit was take the manufacturer weight of the pistons and rods and only balanced the crank. They DID NOT equal the weight of each piston and rod and then balance the crank. Even using the piston and rod's manufacturer weights the crank was off 17 grams on one end. So I wasted $150 paying for Scat to "balance" the kit because I had to have it done correctly afterwards. I called Scat and they told me their balance was good enough and would not refund my money. Live and learn.

You also have to get all the bearing clearances, crank run out, and crank end play checked too. I had my local shop check all the Scat I-beam rods out and they didn't find any flaws what so ever with any of them.