Pinto Car Club of America

I got a wierd problem.  I replaced a window regulator on the  cruiser wagon  ;D I bought.  The car is a 78 and I replaced the regulator with a one out of a 79 HB.  Now the window won't roll all the way done.  It runs out of teeth and leaves the window sticking 4" up.  I matched the regulators real quick and did not notice a difference.  I also tried to adjust the stops which didn't seem to help much.  Are the regulators different between the two years?  Difference between a wagon and HB?