J30 and Q45 rear brakes upgrades for s13

Since 300zx/Skyline brakes and suspension parts are getting very rare and expensive I’m thinking to get J30 or Q45 brake swap for my '90 s13. Front brakes
upgrade is relatively easy to get and do, but what parts I’ll need to swap rear brakes? Infinity J30 11.5" vented rotors are tempting (I plan to get VLSD from that car to) but aluminum spindles from Q45 will help if needed for swap like in 300zx brakes. I will appreciate any advices, links and opinions from you guys.

dont know if this will help with your decision

http://www.ka24development.com/brake_upgrades.html

and i have a nice set of q45 front brakes at a new wicked price

to be honest, 240sx rear brake uupgrades are completely pointless

a good set of pads and nice rotors are all you need

thats why i only bought fronts

J30 uses a similar internal drum e-brake to the Z32, except that the bearing is pressed in to the spindle rather than bolted on, and the backing plates do not have the 4 holes that would secure it behind our type of rear wheel hub/bearing assembly, so they are not as useful as a Z32 setup, becuase you would need new/proper backing plates, however IIRC I test fitted a Z32 rear rotor over one in a local junkyard and it seemed as though the internals shoes, retainer pins, pressure springs were compatible.

Q45 I don’t know about.

Does it mean that to swap J30 rear rotors and calipers I will also need to use whole spindles and hubs from that car? Shocks mountings look similar to the one on s13 spindles.

no, I’m not sure about the need for the rear upright, but backing plate is useless.

you could more than likely bolt them up after re-drilling to 4 lug if neccessary.

Find a junkyard with both a J30 and S13 and test fit before buying

Is not easy to find a junkyard with both a J30 and S13 but I’ll try again tomorrow. Anybody else knows something? I know it has been done but have no links or details about it.

riverbend; kitchener, J30 rear brakes are in the trunk last time I was there.