My ? Is that I have a 96 dx tranny and a 97 ex tranny. I'd like to just swap my 5th gear from my dx and 1-4 off the ex. So I was wondering if I can just swap the 5th gear or do I need to swap the main shaft or ring gear so my final drive isn't diff? Also are the diameters of the shafts the same for the bearings?

 

5th gear is the same.

You can use whichever FD you want, but ring gear and countershaft have to be kept together. Shaft diameters are the same, but bearing OD is not.

 

What can I swap to keep the fifth gear final drive? Couple places state the final drives between the two are diff

 

Both 5th gears are identical in every way. Older D-series Si transmissions in the '92 - '95 Si and Del Sol Si had a slightly lower fifth than the DX (and apparently EX coupes/sedans, which used a transmission otherwise identical to the Si)

If you're trying to lower your RPM in 5th you'll need to swap the final drive, it's going to make your gearing longer/higher for all gears though.