Good to know you are going to upgrade your 120Y with an A15.
Suspension wise, for the rear, it is better to decamber your leaf springs. Blocks are fine, but decambering the springs is a safer and free from worries system.
Once decambered, you use your same existing U bolts and related items. No worries about the blocks loosening up.
You have to get your springs off the car and take them to a shop. It is not an expensive procedure. That will drop your rear about 2 in. You can reverse the eyes of the springs as well, that will lower the car even further. I recommend you decamber the springs. later on, if needed, you can reverse the eyes too.
Shorter rear shocks will follow.
In the front you can take your strut assemblies off the car and you can turn your assemblies into adjustable coil overs.Check the suspension section in here, at 1200 Datsun, the coil over section applies also to the 120Y. Taking the struts off the assemblies, you can cut and weld a piece of threaded metal,and the corresponding threaded spring seat goes in. With shorter springs and the adjustable coil over assembly your 120Y will be ready for cornering.
You can get koni shocks/ struts all around. For a light small Datsun I recommend fluid suspension instead of gas struts/shocks.
Once you have your suspension lowered and improved, a set of sway bars will give you that cherry tip you are looking for. I suggest lowering your car first, before getting any wheels/tires. Only then you will know what fits.
For your coil overs you could get something like Ground Control , or the equivalent in Australia.
Good luck! Show some pictures.
Coil Over Suspension
Transfer
