Will a 5 speed manual work in place of 4 speed in subaru brat?

I have an 1982 subaru brat. I went to a wrecker today and only found one subaru in my year and model range. It was about an 85 with a 5 speed manual with the same engine. I would think it would work except for one issue. The car is a wagon with only front wheel drive but has the same engine and trans setup as mine except it does not power the rear wheels. Is there just a cap over the tailshaft. I'm presuming it will work for 4wd but I want to know before pulling it.

it wont work. the interchange years you are looking for is 81-84 subaru and or brat. 2wd's are not the same as a 4wd. a4 speed will intercahange with a 5speed, and you also can interchange between single range and dual range. the ratio's are on a tag on the final drive. they offer two, 3.90 and 3.70. hope this helps.