One thing that often doesn't get mentioned in these threads is what gearbox are you using? The stock boxes have soemthing like a 2700 drop between gears and a 300 degree cam will make the motor fairly peaky. While competition events one might not mind having to always rev the motor to 7k or more to keep the motor pulling this will become tiresome on the road.
For the record my back up motor has a GX cam in it and it will rev to 8,000 rpms. Note that the head is ported and I run 39 mm carbs coupled to a close ratio gearbox. The car will also trundle along at 2k without protest............the cam that was in the motor when it was my only engine is a 286 duration with .460 lift and that one is quite unhappy below 4K but it will pull nicely to 8600 RPMs..............no way I would run that with a stock gearbox.

Tom

Tom whats the capacity of the GX cammed setup? Mine was A16 and loved it more than the full race grind (model specs forgotten) which was a porker to drive unless you where aggressive all the time. It got pretty tiring.

how to have the option to a close ratio gearbox...

D the GX cam motor is standard 1171cc capacity with the compression up slightly to 11-1, this is the one that is belting out 73 rwhp.

For the A15 I picked up a Delta cam from a fellow member, 278 duration with .420 lift so it will still have some mid-range. Only looking for 100-110 at the wheels......as for the gearbox mine is the mid-close 4 speed, way better than the stock box but not as good as a close ratio 5 speed...............hence my comments on the cam/gearbox relationship. I could build my motor with more power but I would need to upgrade the box................not cheap. The CR 4 speeds are not as sought after so they are a good bit cheaper.

Tom

The Tomei cam is insanely expensive.
Put that money into something like a turbo which will actually give more useful power.

I am presently using a crane 160-0012 in my 1200 engine
lift .441"(in) and .462"(ex)
duration 232 at .050"(in)and 242 at .050(ex)
or 270 (in) and 280 (ex) (advertised)

Pay attention to the lobe seperation angle, it is important.

it struggles to idle under 2000 rpm and they claim a max rpm of 5600 ( they claim valve float at 6200 rpm)

Frankly,on the street, I liked the stock cam better because I did not have to row the car along with its gearbox. My crane cam is not so good for a car that is driven daily. One looses too much mid to low end torque for what little you gain in power.

A yamaha FZ1 has 130 hp @11,000rpm from about the same size engine as the Datsun. If you can find that engine for the price of just a Tomei cam it seems like a no brainer to use a bike engine instead of working so hard on a Datsun engine and getting so little.