Yes I did search and could not come across anything helpful. This is my first civic and I do not like how the rpms are at almost 3.5 when cruising 60-65mph on the highway. Question is, What gear (out of what tranny) could I drop in to lower the rpms at higher speeds? Doing this out of research for future project I will be doing, MPG wise.

 

Sounds like you have an EX civic. A DX or even a VX will have a longer 5th gear. The VX will be miserable, the DX less so.

 

Sis and Del Sol Sis will have a particularly low 5th gear, the EX is geared the same otherwise but has a marginally higher 5th (same as a DX) but it's mostly the final drive that makes it rev so high. You can swap 5th or put a DX transmission in it but personally I'd just leave it the way it is.