I know the '87 2.5 DT's and understand the 2.6 gassers have a physically larger differential than your '85. They will still swap over if you also use the matching rear section of the drive shaft and the rear axles - a lot of extra trouble and probably too tall of a diff anyway for your car.

Are you asking what models had the same differential ratio as your '86 2.5 manual? If so, post the number stamped on the side of your current differential so you will know the ratio your after.

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