Who has ported iron heads

[SSDiv6]

In the past, I have used Seal-All Polymer sealer and Fluid Weld from Goodson succesfully.

http://www.goodson.com/store/templat...l.php?IID=5928

http://www.goodson.com/store/templat...81f3db16807e8e

[Jeff Teuton]

K & W Block Seal. We always keep a few cans around. Works real well.

[SSDiv6]

The GM pill and the K&W is only good for a running engine. If the engine is dissassembled, then use the Goodson stuff.

If the engine is in the car, the best fix is Sodium Silicate; also know as Water Glass and Egg Glass. If you use Sodium Silicate, first is drain all the water or coolant, flush radiator and engine with water. Fill radiator with just water and add some about 4 to 8 ounces of sodium silicate to the radiator. Do not use a lot because it can clog the water pump and/or radiator. Let engine run until fully warmed up and then run it for at least 15 to 20 minutes. Let engine cool and drain. Remove all the spark plugs and keep the carburetor or throttle body open so air will circulate and wait 24 hours. Sodium silicate is the only long term cure I have seen.

Another product I have used for engines that are running is Thermagasket. It also works great.
http://www.rxauto.com/

I always put the GM pills in the cooling system for any engine build or rebuild; especially with aluminum cylinder heads. The procedure is used by GM with all the Northstar engines, the LQ1 and Quad-4 engines. Jaguar also recommends the use of the GM pills Bars Leak or K&W for all engine rebuilds.