Almost ready to start my Impala. It has worked aluminum LT1 heads on it. Started filling it with coolant and noticed a leak. I thought I just hadn't put enough thread sealant on it. Took the header off and saw the #8 exhaust port was leaking coolant. You can blow on the line and after a few seconds start seeing coolant coming out. I can't see any visible cracks so I'm not sure what happen. I took them to the machine shop that replaced the valves and guides and milled them and they said it was nothing they did. They said they were ported too much and probably cracked when I torqued them. The port/polish job is several years old and they weren't the ones that did it. They said they don't weld aluminum there but knew a place that could. Does anyway have any suggestions on where to send the head to have it fixed? Should I go ahead and send the other one too even though it wasn't leaking?

 

Probably cracked? Did you pull the head and have the head pressure tested?

 

Have them both pressure tested to make sure you find the leak(s). It will probably be around $30 a piece but can be a whole lot cheaper in the long run if you have a leak you don't catch till the car is together, like the situation you are in now.

 

The machine shop pressure tested it and said it leaks. I could see it leaking before I pulled it off. Assumed it was the jacket that got nicked or cracked some how.

They didn't charge me for the first one so I might as well go ahead and at least have the other one checked.

They don't weld aluminum in house so I was looking at my options for sending them off somewhere.

 

I would say use whomever your trusted shop recommends.