I have a 1991-99 Ultima 6 speed tranny and a 1989 1340 evo engine. What year or years of primarys will work with this combo? Thanks for the help

 

You'll have to change out your transmission mainshaft.86-89,90 and 91-06.

 

The simplest way is to use a clutch assembly for a 1990-1993 model year.

Your primary gearing and starter gearing will not change.

 

What Dan said may be the least expensive and more simple way for you to go if you don't do your own wrenchin'.

 

Thanks for the help