Why is your engine being rebuilt for second time in 200K?
On most engnies head problems are more common than problems with the bottom
end. In theory new heads are a good way to go. The reality is that the
quality of the replacement heads present another set of concerns.

If the casting is good, (no cracks, straight, tolernaces etc,), new guides,
valves, proper machining and facing of seats there is no reason used heads
can't go the distance. If an outside influence such as a cooling system
failure occurs new heads will melt, crack, and warp, just as well as the oil
ones anyway.

As you are going for rebuild #2 I would be more concerned about the case,
especially for the 1.9L. And yes machine can mess up these heads big time.
Especially pressing in new valve guides.

Dennis

>From: B Feddish <bfeddish@NETREACH.NET>
>Reply-To: B Feddish <bfeddish@NETREACH.NET>
>To: vanagon@GERRY.VANAGON.COM
>Subject: New vs. machined heads,              a spinnoff of Engine
>Replacement or Gasket Fix?
>Date: Fri, 22 Aug 2008 08:38:01 -0400
>
>I'm going to be in the same situation as Robert this winter and I'll be
>having my 1.9 rebuilt. One of the big expenses appears to be the heads.
>What is the advantage of buying new heads, vs, reconditioned heads vs.
>having a machine shop do them?  Let's say my current engine has gone 80K
>miles on it's last set of machined heads. That was fine with me as the
>rebuild was dirt cheap. Am I only getting longetivity with new heads or are
>they much more reliable?  Can the machine shop do it "wrong"?  Are
>reconditioned ones a good compromise?
>
>Heads come up allot here and I'm trying to determine if that extra $1000
>expense is worth it if I'm fine with my next rebuilt not being able to make
>it to 200K.
>
>
>
>Thanks,
>Bryan