I have found a 1/3rd inch long crack in a block a few inches below deck-could it be drilled out and put a plug in? ANYONE seen this before? Thanks if you can help!

Joe,
How about some more details as to exactly where the crack is on the block ? Outside ? Inside ? In a cylinder ? Where are you located ?

Yes it can be fixed, but you need to be talking with a machine shop. If I remember correctly the procedure is refered to as "stiching". There was a decent article on this in a 1996 issue of Chevy High Performance. Sorry, don't remember the month, I only remember it becuae I bought my chevelle right around that time.

Bill I am close to Ft.Benning GA. The crack is Exterior-Barely drips when cold stops once running! Could I drill a small hole and tap it then put a brass plug in?

JD,
Problem with just drilling & putting a plug in is you may not get the ends of the crack.
Best way is with "stitching pins" & the best pins are made by LocknStitch.
You want to mag the crack to be very sure you have the ends captured or it will grow.

Check here for more info:
LocknStitch (http://locknstitch.com/)

I have also had very good luck fixing cracks like this with an epoxy called
"Splash Zone A-788"
This is a thick 2 part marine epoxy that is used to repair boat hulls & bridge abutments.
It can be used to fill & shape cylinder head intake ports among other things & it can even be used underwater.
Good stuff
Biggest problem with the epoxy method is cracks in cast iron tend to keep going unless you drill a hole in each end to "capture" it