I want to swap the original lightbulbs on my 240z with LEDS. Which model will be ideal to obtain the brightest result and definition? I want to keep the original stock look but with more brightness on all the gauges.

Will this one work for all the gauges? 1972 Nissan 240z Instrument LED Lights | LED Replacement Bulbs for Cars | 12v | Super Bright LEDs | Super Bright LEDs

Later on i would like to accomplish the same with the rest of the car lights.

The original 3 watt bulbs in the instruments have a round glass sphere that sits in a green plastic hemisphere to give the instruments a bluish white illumination. The BA9s bulbs will fit in the socket, but because of the oblong plastic envelope of these bulbs, the bulbs will hit the green hemisphere and will not allow the socket to seat.

Depending on how original you want to keep your Z, you could remove the green hemispheres though this will require you to remove the instruments. Otherwise, you can get strips of LEDs that aim off the side of the mounting strip (as opposed to pointing away from the surface). These can be mounted in the instrument can so that light is pointing towards the dial. This also requires removing the instruments.

My recommendation: Abort the LED mission. Pull the gauges, clean the insides, paint the inside walls white and use new brighter bulbs. If that isnt enough bypass your dimmer:

http://www.classiczcars.com/forums/electrical-s30/51875-converting-led-bulbs.html

My recommendation: Abort the LED mission. Pull the gauges, clean the insides, paint the inside walls white and use new brighter bulbs. If that isnt enough bypass your dimmer:

http://www.classiczcars.com/forums/electrical-s30/51875-converting-led-bulbs.html

So if i swap them with leds i wont have a brighter look inside the gauges? can you point exactly which bulbs shall i puchase then? maybe on amazon or another reliable source? please specify model.

So if i swap them with leds i wont have a brighter look inside the gauges?

Correct, they wont be brighter. I used these: #3893 MINIATURE BULB BA9S BASE, T2 3/4 12V .333A, 3893,#3893,#3893 MINIATURE LAMP,#3893 MINIATURE,#3893 BULB, #3893 LAMP, #3893 INDICATOR, EIKO#40659

The real problem is that these gauges have bulbs in the back, that reflects off the sides and actually are lit from the front. LED lighting doesnt reflect well so it doesnt come out looking that great