Don't worry about the 'high revs'. These Datsun A-series engines can ran 4500 RPM all day long.

If you lower revs by a) taller diff gear or b) taller tires, you lose acceleration. The 5-speed has noticeably taller gears 1-2 (compared to 56-series 4-spd) so you'll lose some acceleration there too. But this makes the gearbox a 'closer' ratio so one you get rolling it's OK.

At $800-$1200 I think it is a no-brainer. Just say no to a 5-speed. Both my 1200s still have the 4-speed. I just got back from 800km drive at speeds of up to 120kph with a 4.11 diff and 14" tires. Another advantage to the 4-speed is that at highway speeds, it is in the fat part of the torque curve and so is very responsive. With a 5-speed you have to down-shift for passing and for mountain grades.

I may go to a 5-speed eventually, as we can find them as cheap as $200 here. But that's mainly to make it quieter on the highway, and get better fuel economy. Certainly it won't help performance.

okay,
thanks heaps for that dd
i didnt realize they were so expencive hey
if i was to get a tacho, what should the face redline at?
or is there another model datto that had the a12 but came with a tach?

im not sure if the 1200 coupe came with them
But the 120y coupe did
I have one in my y
With 15 inch wheels (not sure of tyre)

4th gear at 80 is close to 3000 rpm
While 5th is close to at 80 is close to 2200 rpm

And dd is right about the 4th gear having good power at the speeds you really notice the diference

Redline is 6000-7000 depending on the tach you get. I doubt if you'd rev that high by accident while in gear. It won't break the engine to go to 7000 but it slows down at 5000 RPM if you are using the stock head and manifolds. So it's difficult to rev it it past 6000 with a stock engine.

120Y



1200 Ute

okay, i have extractors on it and a straight through exaust system
so are these tacho's easy enough to come by?

Yes they are for sale often enough.