I'm ready to reassemble everything and my manual says yes but my bro says no.

HELP!!

What manual? If it's the Subaru service manual, go by what it says. My XT6 service manual says to use a new head gasket, but doesn't mention gasket sealer.

 

I don't use gasket sealer on any gaskets. Some types of sealer are very difficult to remove, and scraping will damage the aluminum surfaces of the block and the head, leading to expensive and difficult machining later..

 

My vote is "no".

 

Some advice:

Clean the threaded holes in the block with a thread chaser. Thoroughly clean the head bolts too. Oil the bolt threads before installing. (Very important, to avoid stripping the threads in the block!!!)

 

You can make a thread chaser from an old head bolt or some other type of bolt with the same thread. Using a hacksaw, cut two slots cross-wise about half the length of the thread.

 

Turn the thread chaser into the hole you want to clean until it starts to bind, then back it out all the way and clean the slots. Repeat until you can thread the bolt in all the way by hand. Be patient, don't hurry this job.

I always use a little of the Permatex copper spray on head gaskets. Although someone from this board (Cameron) pointed out to me that copper and aluminum react chemically, I still use the copper spray. A trusted mechanic friend recommended it to me.

 

Also, I torque the bolts to 51 ft/lbs and skip the retorque that the manual suggests.

 

Good luck!