AC Delco Seal Tabs

[Tom Goldman]

The GM "horse pills" saved my butt many times when I ran welded GM 074 castings.
Subaru also has a sealer that works amazingly well and its cheap, about $1.50 for a 3 oz bottle. they call it a "conditioner" but it really works on leaky heads and since its a liquid ,it doesn't block up the rad passages.