Yes, but with a final drive ratio change.
When I still had my Mk1 MX-5 I looked at various ways to raise the gearing a bit - 3000rpm for 60mph in 5th seemed daft in a car that could easily be used for longer distance touring. I found it wearing just on my normal commute. The simple answer was the later 6-speed, except that 6th was only just a shade taller than 5th on the earlier box. Gave up in the end and decided that with rapid sill rot it wasn't a car for me to keep...
Just for comparison the T16 +4 with R380 box was geared so that 3k rpm gave approx 75 in top - nice long legs for distance work...
Cheers,
