Auto Parts: alero 3.4 cylinder heads, hollander interchange, piston crown

Question
QUESTION: i have 2001 3.4 v/6
alero i want to know if 3.1 v/6 cylinder heads will interchange

ANSWER:      It would depend on the year of the 3.1 heads, and the type of 3.4.  How on earth did you manage to crack a 3.4 head?  They are pretty strong.  GM used a lot of different combustion chamber designs in these engines over the years, and the new heads will have to be compatible with the shape of the piston crown in the 3.4.  I would just get reman heads for the 3.4, and avoid all of the trouble that might result from attempting to modify something else to fit.

---------- FOLLOW-UP ----------

QUESTION: i managed to crack both of them!! all 6 cylinder have a crack between the valve and the spark plug! the motor is a 3400 sfi of course a 3.4 liter. its in my 2001 alero gls model. i can find a bunch of 3.1 heads but not very many 3.4. alot of places i look for heads at say 3.1/3.4 v6 heads. i just wanna make sure they work before i waste the cash on them!
thanks!!

Answer
    If you're looking for used heads, the yard will have a Hollander interchange that tells them whether or not they will work for you.  It's always right.  If you are looking for remanufactured heads (a better bet), all of the vendors want the casting number off of the old one.  That is the best way to ensure that you are getting the right new one.  They also want to know if the head is set up for air injection.  If you supply those two facts, any competent parts vendor should be able to supply the right item.