davemurray

I've been experiencing lack of power for a long time, I heard it could be due to compression problems, so I decide to take out the heads of my 1989 GT and the head gasket was in good condition, my last guess for massive loss of power is worn seats and valves. Could that be?
Is it worth doing a valve job instead of changing the stock heads?

I3atR!ce

did you happen to do a compression test before you ripped into the motor too see if that was even the problem?

JD1969

I 'd be looking for worn out rings first.

davemurray

A friend of mine did one on my stang back in 1998 and it had bad compression I'm askng him today if he remembers the #'s.

mkspeed26

replacing the heads will not fix a compression issue (unless the gasket is busted). u need to replace the rings to fix compression problems

angcobra

Valves or rings can be a cause for loss of compression. To tell the difference between the two is normally done with a cylinder leakage test. But, of course this is done before removing the heads.
You can have the heads tested to see if they have leaking valves.
As far as rework the stock ones or getting aftermarket heads, that all depends on your performance desires and your budget.