changing gear ratio in 4g civic?

I've been busy upgrading my 88 hatch- my 1st Honda, bought maybe 3
months ago. Thought I'd finally focus on the drivetrain some, and
figured the 4-speed tranny would be the 1st thing to go. I
guessed/assumed that the typical 4G civic 5-speed tranny would NOT be
close-ratio, would likely have a taller top gear than my 4-speed, but
would likely have a shorter 4th gear than my 4th. In other words, I
assumed any 5-speed would give me at least a slightly closer ratio
between gears. So, you can imagine my disappointment (umm, aka how
stupid I feel) having just discovered the 5-speed I pulled from a CRX
and just got done installing in my car has a 3rd gear taller than top
gear! Then, suddenly I remembered some snippet of info I'd heard over
the years about CRX HFs, high fuel economy, and bizarre gearing... So,
the (blindly optimistic) question is:

Can I just swap the ring and pinion from my 4-speed into this 5-speed
(both are 88') to change ratio?

 

it's not worth the effort - just go straight to the 5-speed box and
enjoy. 3rd, 4th & 5th are relatively close ratio and fun to use.

and while you're in upgrade mode, go to a junk yard and pick up a cam
from a dx or si /and/ modify the tandem valve stop so it opens fully.
and get the dx manifold.

 

should add: use a 5-speed box from anything /but/ the hf!

[because it's restricted on the std, the one you have]