New Shift Linkage, suddenly won't select third gear

[aldad138]

I have read enough of these type of threads to know, linkage can be problematic.  I had the linkage swapped out, with the nice poly set from John Montgomery, last year.  I have suddenly sorted out most of the gremlins, and the is running strong, but now does not want to shift properly. 

My mechanic, that did the work, is out of the picture and I am a newbie.  If I get in there, what am I looking for to determine if the bushing set was not installed properly, or how to correct it?  Should it be obvious what the problem is, or something like an adjustment to the metal rod linkage?  I am working and learning as I go...

I must say that even with just 1st, 2nd and 4th this little Coupe is fun.

Alex