1-4 are great but the car is screamin on the freeway...a 6th gear would be great! is it possible to change the 5th gear ratio to lower rpms' on the freeway?

thanks! Ive already searched for this and was unable to come up with an exact answer...

 

I'm sure it could be physically done but would most likely involve custom machining work at a minimum. I've not come across any places that sell pre-made gears to change your ratio on a given transmission.

 

For a D series? Look at a transmission from a 92-95 Civic VX. However, you would be looking to convert to a hydro transmission.

For a B series? It is common to see people install 5th gears from an Integra LS transmission for better highway driving.

 

it's the stock motor. 1990 Si--so a d series...when you say hydro you mean a manual with a hydraulic clutch correct? not an automatic? sorry Ive only owned american muscle before so a hydro is a generally a 3 speed auto trans..

what kind of cost is involved to swap the tranny? is this a junkyard swap or an expensive aftermarket item?

thanks

 

you can change the fifth gear on the main and counter shaft, require tear down in the tranny..

 

Hydro clutch, yes. Reserach it and you can get an idea of prices. I have never played with 88-91, so I know nothing about them.