when somebody clearenced my block for a stroker crank, they hit into the water jacket, now has a slight leak. Whats the best block sealer out there?

If it's still apart you can either weld or use that good epoxy they use on heads. I think you can get it from Shady Dell or Reher Morrision. If you want something to dump in the radiator I have had good luck with Barr's. Get the silver stuff that looks like glitter.

Irontite ceramic but cannot be used with antifreeze
irontite has some other ones for antifreeze!
http://irontite.com/store/index.php?main_page=product_info&cPath=1&products_id=1

looks like after you run it then leave it sit with this you can add coolent with another sealer suggested???

Try and find some K&W block sealer

I have a little water in no. 7 cyl. the engine rebuilder said whoever built it, got into the water jacket when they were grinding crank clearance. they had block hardener on it but I still have a small leak

ther is no antifreeze but there is wet vetter

We used the blue devil sealer (about $50/bottle). I've heard the Moroso cermanic seal works good too and it's cheaper.