Motor Problems Resolved & A Question
 

My brother and I pretty much figured out what was wrong with the motor. The surging problem was a symptom of a bad auxillary air regulator. We took it apart and cleaned it up and now it is closing when it gets warm. The other problem with the motor cutting out at 3,500 rpm had to do with the distributor. Our troubleshooting kept leading us back to the distributor, so we put another one in for a test and no more problems. Oh it feels good to track down and fix these problems.

Question, can you swap out an older "brain" for a newer one with the mixture adjustment? Is anything else required or cautions that need to be taken. Is this a good idea in the first place?

As far as I know, there are no really significant changes among the 1.7 and 2.0L brains. The '73 brain can even be used for either the 1.7L or the 2.0L

-Wayne