I'm 6'4" and had problems fitting into my 4G Prelude which uses basically the same seats and floorpan.

I found that I could get a good seating position in the cab but it was too far for me to reach the gearshift and steering wheel comfortably. Leg room was perfect.

I solved this by installing a 65mm spacer between the boss kit & the momo steering wheel. You can't do this with an OEM wheel, you will have to go aftermarket if you want a spacer.

I also installed a JTC Short Shifter and the JTC Shifter Extender kit. The SS shortened the gear throws by 1/2 so it was less "reaching" to get to 3rd and 5th and the Extender bits ( 1.5" bend + 1.5" straight) made it an easy reach to the gear knob. It uses the OEM thread if anyone wants to use it on an OEM shifter.

Having the SS adjusted to the "tightest" setting lowers the gearstick so the extra extensions take it back to only 2 inches taller than stock with the bend. I had a new leather gearstick boot made up that was a few inches longer than OEM and a bit "fatter" at the top to allow for the bend and still have the OEM gear knob installed. It doesn't look too different from stock and probably wouldn't get noticed unless you knew the model.

I'm using OEM 4G Leather seats and stock rails & the driving position I now have is perfect, probably the best I've ever had in a car I've owned. Only downside is using the wiper & indicator stalks but seeing as its not a daily & only goes on runs in the countryside it's not really an issue for me.

The new position did take some getting used to, my head is parallel to the start of the rear 1/4 glass when I drive and I can only see about 2/3 of the bonnet (which isn't usual when you are 6'4") but once I got used to it was great. I used to dislike driving my lude until I made the shifter/spacer mods and being cramped actually made it tiring to drive, now it's something I can drive for hours.