i just acquired a 93 prelude si (h23a1) - all stock.

when i drive in top gear at 70mph, the tach is around 3700rpm. at 70mph, my 95 accord (f22b1) revs at only 2800rpm. i know it's a different engine and tranny, but it seems like the prelude is revving too high.

is 3700rpm normal for 70mph cruising on a 4th-gen prelude?

 

yep.

The H23 is going to seem the worst, too. Lowish redline, but gearing that is like the H22's.

 

compare the gear ratios, i cant help you on that but it doesn't seem too off. I know the gears on the h23 tranny are taller than an h22, so im guessint th 3000 or so RPM u have left should carry you pretty far up.

 

I have a JDM H23A mated to my original Si's M2S4 tranny(same as yours). It runs 80mph @ 4k. Shorter gears are a great thing except on the highway. If I want to drop my vtec engagement to 4500rpms, then I will be cruising around on the interstate in vtec, wasting gas. Oh well. If it bothers you that much my suggestion is: replace the final gear...and while your in there: LSD.