Stock heads

Is it worth porting and polishing stock heads on my mustang? Anyone done it?

Some would say yes
and
Some would say no

Its all about what you expect to happen
or
What your goals for your combo are

Its a no brainer that they would not give the same gain
as
A set of better flowing, newer technology, Aluminum heads

If I was to guess at how much power you'd pick up ...........
Depending upon quality of port work, valve work and the like

I'd say they would give 1/2 to 2/3 the gain of TFS, AFR, Edel, etc.

Grady