I have a 1990 base model Civic hatchback and am thinking about swapping the 4 speed Manual Transmission with a 5 speed. I have been doing some research and some sites say that as long as I use a 89-91 EF 5 speed transmission, it would be an easy swap of the transmissions. Other sites say that I would need to get new Steering Knuckles and new axles since they would not fit. Some say that it is totally worth it, while others say that even though you can add the 5th gear, the base model engine does not have enough power to accelerate in 5th gear, so it wouldn't make much of a difference. I am a little confused and would like to know which is true before attempting this swap. I am new to working on cars and have been learning things slowly. Any help is appreciated!

Thanks

 

Yes it would make a diffrence you just wont notice it.
Shorter gears than the 4 speed.

You can use your stock steering knuckles and axles.